To see the other types of publications on this topic, follow the link: Muscles agonistes.
Dissertations / Theses on the topic 'Muscles agonistes'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Muscles agonistes.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Le, Bozec Serge. "aspects et bases de la synergie des muscles agonistes chez l'Homme." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37599038x.
Full text
2
Zinoubi, Sana. "Exercices et entraînement en co-contractions isométriques volontaires des muscles agonistes- antagonistes : facteurs d'influence." Thesis, Paris 10, 2015. http://www.theses.fr/2015PA100187/document.
Full textAbstract:
L’objectif général de la présente thèse était d’étudier les effets et les facteurs d’influence des exercices et des programmes d’entraînement consistant en la co-contraction maximale isométrique volontaire (CCMIV) de l’articulation du coude : effet de l’entraînement en CCMIV sur la force explosive (Etude A), influence de l’heure habituelle d’entraînement (Etude B) et de charges additionnelles pendant les CCMIV (Etude C). Les résultats ont montré que 6 semaines d’entraînement en CCMIV peuvent améliorer simultanément la force maximale volontaire des muscles sans altération de la force explosive (Etude A et B) et indépendamment de l’heure habituelle d’entraînement (Etude B). Ces gains de force s’accompagnaient d’une augmentation de l’activité électromyographique des muscles agonistes (Etude A et B). Cependant, les résultats de l’étude B suggèrent que l’entraînement le matin s’accompagne d’un meilleur gain de la force musculaire, masquant ainsi les différences de force entre le matin et le soir. Par ailleurs, l’étude C a montré qu’une charge additionnelle (50% FMV) associée à une CCMIV modifie le pattern d’activation des muscles agonistes-antagonistes : augmentation du niveau d’activation des muscles agonistes et diminution de celui des antagonistes. Par conséquent, un programme d’entraînement en CCMIV avec charge additionnelle devrait comprendre des exercices avec charge pour les fléchisseurs et les extenseurs. De plus, les résultats de l’étude C suggèrent que le concept du fléchisseur équivalent pourrait être appliqué non seulement quand les fléchisseurs agissent comme agonistes mais aussi quand ils agissent comme antagonistesThe aim of the present thesis was to study the effects and the influencing factors during the elbow joint maximal isometric voluntary co-contractions (MIVCC) exercises and training program: effect of the MIVCC training on the explosive force (Study A), influence of the time-of-day at which training was scheduled (Study B) and additional load during MIVCC (Study C). The results showed that six weeks of MIVCC training can simultaneously improve the maximum voluntary force, without altering the explosive force (Study A and B) and independently of the time-of-day at which training was scheduled (Study B). These improvements were accompanied by an increase in electromyography activity of agonist muscles (Study A and B). However, the results of study B suggest that morning training is accompanied by a higher strength improvement, by masking the strength differences between the morning and evening. Furthermore, the study C showed that additional load (50% MVF) associated with MIVCC modifies the activation pattern of the agonist-antagonist muscles: by increasing the activation level of the agonist muscles and decreasing the co-activation level of the antagonist muscles. Therefore, MIVCC training program with additional load should include exercises with load for flexor and extensor muscles. In addition, the results of the study C suggest that the concept of “flexor equivalent” may be applied not only when the flexor muscles acting as agonist but also when they acting as antagonist muscles
3
Bejaoui, Khémissa. "Les réflexes d'étirement des muscles fléchisseurs et extenseurs du coude : comparaison entre muscles agonistes : essai d'identification dans le transport manuel d'une charge." Paris 11, 1986. http://www.theses.fr/1986PA112349.
Full textAbstract:
Ce travail a eu pour but de comparer l’activité myoelectrique réflexe de différents muscles d’un même groupe agoniste, en réponse à leur étirement passif et d’essayer de déterminer l’intervention possible de ces mécanismes réflexes lors d’une activité naturelle comme le transport d’une charge. Une première partie est consacrée à l’étude des muscles extenseurs du coude, l’anconeus et le triceps brachii. Une seconde partie traite de l’activité des muscles fléchisseurs du coude : biceps brachii et brachioradialis en réponse à l’étirement passif et lors du transport de charges. L’étirement des groupes musculaires est provoqué sur un fond d’activité tonique afin de se rapprocher le plus possible des conditions naturelles. L’enregistrement porte sur les activités électromyographiques de surface et sur les variables mécaniques : déplacement, vitesse et accélération du mouvement passif. En réponse à la flexion passive du coude : l’amplitude de la réponse monosynaptique (M₁) et de la réponse réflexe tardive (M₂₋₃) des deux muscles extenseurs du coude est plus importante lorsque le coude est initialement plus fléchi ou/et lorsque le niveau d’activité tonique initial du triceps brachii est plus élevé. La latence des réponses, dans ces conditions, est aussi légèrement plus brève. L’amplitude des activités EMG réflexes des deux muscles fléchisseurs du coude augmente en fonction de l’accélération de l’étirement et se stabilise pour les accélérations les plus élevées. Il n’existe pas de différence significative entre les activités EMG réflexes des deux muscles extenseurs, ni entre celles des deux muscles fléchisseurs du coude. Le rapport de l’amplitude de la composante M₁ à celle de la composante M₂₋₃ ne va pas dans le sens d’une activité réflexe monosynaptique plus importante pour les muscles fléchisseurs que pour les muscles extenseurs. Lors du transport d’une charge : il existe, à la suite du contact du talon avec le sol, lors de la marche, une augmentation rapide de l’activité EMG du brachioradialis compatible avec un réflexe d’étirement.
4
Bejaoui, Khémissa. "Les Réflexes d'étirement dans les muscles fléchisseurs et extenseurs du coude comparaison entre muscles agonistes, essai d'identification dans le transport manuel d'une charge." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37595791b.
Full text
5
Charissou, Camille. "Etude de la contribution du couplage intermusculaire au contrôle de l’activité des muscles synergistes agonistes et antagonistes lors de contractions isométriques volontaires." Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0122/document.
Full textAbstract:
Le corps humain possède une grande redondance musculo-squelettique, se traduisant par une infinité de coordinations musculaires possibles pour produire un effort résultant. Lors d'un mouvement, le système nerveux central est confronté à la gestion de cette redondance. A travers l’analyse de cohérence entre les signaux électromyographiques, ce travail de thèse étudie le rôle fonctionnel du couplage intermusculaire et explore la contribution des mécanismes nerveux impliqués dans la régulation de la redondance musculaire en termes de contrôle de l’activité des muscles agonistes, et antagonistes impliqués dans le phénomène de co-contraction. Nos résultats ont révélé que le couplage intermusculaire entre deux muscles agonistes est modulé en présence de fatigue et en fonction de l’expertise sportive. De plus, le couplage entre muscles agonistes et antagonistes dépend des contraintes mécaniques et du rôle fonctionnel des muscles, et semble directement lié au niveau de co-contraction. La cohérence intermusculaire est modulée dans plusieurs bandes de fréquence, témoignant de l’implication de différentes commandes centrales communes d’origines spinales et supra-spinales. Nos conclusions amènent à penser que la coordination musculaire est en partie contrôlée par des commandes nerveuses communes dont la contribution est modulée suivant les propriétés fonctionnelles des muscles concernées, pour s’adapter de manière optimale aux contraintes internes ou externes de la tâche. Les travaux déjà engagés proposent de contribuer à une meilleure compréhension des mécanismes sous-jacents l’altération de la fonction motrice chez des patients cérébro-lésésThe human motor system is characterized by high musculoskeletal redundancy, implying that a given resultant effort can result from infinity of feasible muscle coordinations. During a movement, the central nervous system has to manage such redundancy. Through coherence analysis between electromyographic signals, this thesis work aims at investigating the functional role of intermuscular coupling and at better understanding the contribution of central nervous mechanisms responsible for the regulation of muscle redundancy, in terms of agonist muscle activity and also antagonist muscles activity involved in co-contraction. Our results revealed that intermuscular coupling between agonist muscles is modulated according to both the fatigue level and the training status. We also showed that the coupling between agonist and antagonist muscles depends on the mechanical configuration and functional role of muscle pairs, and seems directly related to co-contraction. The modulation of intermuscular coherence occurs in several frequency bands, suggesting the involvement of different common central drives of spinal and supra-spinal origins according to task constraints. Taken together, our results lead us to conclude that common neural drives take part in the control of muscular coordination, with different relative contribution according to the functional properties of recruited muscles, in order to optimally adapt to both internal and external task contraints. Work already undertaken proposes to provide a better understanding of the mechanisms underlying impairment of motor function in brain-injured patients
6
Gayral, Stéphanie. "Prolifération et différenciation des cellules musculaires lisses aortiques : implication des messagers phospholipidiques nucléaires." Paris 7, 2007. http://www.theses.fr/2007PA077071.
Full textAbstract:
La prolifération et la différenciation des cellules musculaires lisses vasculaires (CML) sont impliquées dans le développement de l'athérosclérose et de la resténose post-angioplastie. Des études récentes montrent un métabolisme lipidique intranucléaire autonome impliqué dans ces deux processus cellulaires. Toutefois, peu de travaux ont concerné le métabolisme nucléaire du phosphatidylinositol-3,4,5-/ràphosphate (PI(3,4,5)P3) et des phosphatidylcholines (PC). Nous nous intéressons donc plus particulièrement aux voies de signalisation impliquant ces deux métabolismes dans des noyaux purifiés de CML. Nous avons pu identifier pour la première fois la présence intranucléaire des 3- et 5-phosphatases actives, PTEN et SHIP-2, dans les CML. D'autre part, nous avons montré que seule la phospholipase Dl (PLDl) est exprimée dans le noyau des CML, alors que la PLDl et la PLD2 sont présentes dans les CML. Les agonistes des récepteurs couplés aux protéines G, comme l'acide lysophosphatidique (LPA) induisent une augmentation de l'activité PLDl, alors que les agonistes des récepteurs à activité tyrosine kinase n'ont pas d'effet significatif. Nous avons précisé que l'activation de la PLDl nucléaire par le LPA implique une voie PI3K/PKCζ, et la translocation de la PKCζ, ainsi que l'activation nucléaire de RhoA. Nos résultats indiquent aussi une régulation de la PLDl intranucléaire au cours de la modulation phénotypique des CML. Ainsi, la caractérisation des enzymes associées au métabolisme endogène du PI(3,4,5)P3 et des PC dans le noyau des CML pourrait aboutir à l'identification de nouvelles cibles thérapeutiques dans le traitement de pathologies fibroprolifératives de la paroi artérielleVascular smooth muscle cells (VSMC) proliferation and migration are hallmarks of atherosclerosis development and postangioplasty restenosis. Recent studies highlight the existence of an autonomous nuclear lipid metabolism related to cellular proliferation and differentiation. However, the importance of nuclear phosphatidylinositol-3,4,5-Jn'sphosphate (PI(3,4,5)P3) and phosphatidylcholine (PC) metabolism is poorly understood. Therefore, we are interested in nuclear phosphatase and phospholipase identification which hydrolyse PI(3,4,5)P3 and PC respectively, in second messengers implicated in proliferative and differentiative signal pathways. For the first time, we identified active intranuclear 3- and 5-phosphatases PTEN (Phosphatase and tensin homolog deleted on chromosome ten) and SHIP-2 (SH2 containing-inositol 5-phosphatase) in membrane-free nuclei isolated from pig aorta VSMC. On the other hand, we demonstrated that only PLDl is expressed in VSMC nuclei, while PLDl and PLD2 are present in VSMCs. Moreover, specific G-protein coupled receptor agonists, like lysophosphatidic acid (LPA) induced an increase of intranuclear PLD activity, whereas tyrosine kinase receptor agonists have no significant effect. We also showed that LPA-induced nuclear PLDl activation implied PI3K/PKCζ pathway activation and PKCζ. Nuclear translocation as well as nuclear RhoA activation. Interestingly, we also demonstrated that PLDl is regulated during phenotypic modulation of VSMC. Thus, the characterization of an endogenous PI(3,4,5)P3 and PC metabolism inside VSMC nucleus, and their associated enzymes, provides new perspectives in the control of vascular fibroproliferative disorders
7
Joassard, Olivier. "Mécanismes moléculaires du contrôle de la masse musculaire sous l'action du β2-agoniste formotérol." Phd thesis, Université Jean Monnet - Saint-Etienne, 2013. http://tel.archives-ouvertes.fr/tel-01001862.
Full textAbstract:
Les β2-agonistes sont couramment utilisés pour prévenir et réduire les symptômes de l'asthme et de la bronchoconstriction induite par l'exercice. Mais, pris en quantités supérieures aux doses thérapeutiques, les β2-agonistes ont un effet anabolisant qui a été clairement démontré in vivo. Un certain nombre d'acteurs sont mis en jeu dans la réponse biologique du tissu musculaire aux β2-agonistes. L'un de ces acteurs est la voie de signalisation PI3K/Akt/mTOR, voie d'initiation de la traduction, ayant un rôle majeur dans la synthèse protéique. Dans ce contexte, notre première étude avait pour objectif de déterminer la cinétique des événements moléculaires responsables de l'hypertrophie du muscle squelettique de rat après administration de formotérol pendant 1 jour (J1), 3 jours (J3) et 10 jours (J10). Nous avons montré que l'administration de formotérol induisait une hypertrophie musculaire à J3 et J10 associée à l'activation transitoire de la voie de signalisation PI3K/Akt/mTOR (J1 et J3), et à une diminution de l'expression de l'E3 ubiquitine ligase MAFbx/Atrogin-1 (J3). La voie autophagie lysosome ne semblait pas être affectée. Ainsi, l'ensemble de ces résultats suggère que l'activation de la voie PI3K/Akt/mTOR est associée à la voie ubiquitine-protéasome mais pas à la voie autophagie-lysosome. La régulation transitoire de la voie PI3K/Akt/mTOR suggère que d'autres voies de signalisation sont impliquées dans l'hypertrophie musculaire induite par le formotérol. Le 007-AM, analogue de l'AMPc, a été décrit comme pouvant stimuler la voie de signalisation PI3K/Akt/mTOR via l'activation de la protéine Epac, suggérant que le 007-AM puisse constituer une molécule de substitution à l'utilisation des β2-agonistes. Notre seconde étude avait pour but de déterminer si le 007-AM avait une action anabolisante sur le tissu musculaire, mais également de déterminer si la 007-AM était une molécule stable permettant d'envisager son usage dans un cadre pharmacologique. L'administration de 007-AM pendant 7 jours chez des souris n'engendrait pas d'hypertrophie musculaire. En revanche, in vitro sur cellules C2C12, le 007-AM activait la voie de signalisation PI3K/Akt/mTOR comme en témoignait l'augmentation de la phosphorylation des protéines rpS6 et 4E-BP1. Nos résultats montraient également que le 007-AM était instable dans le plasma alors que son produit de dégradation, le 007 était plus stable. Pris ensembles, ces résultats suggèrent qu'un traitement de 7 jours au 007-AM n'est pas suffisant pour induire une hypertrophie musculaire et que l'absence d'hypertrophie musculaire pourrait provenir de l'instabilité du 007-AM dans le plasma. Toutefois, des études supplémentaires seront nécessaires pour confirmer ces résultats
8
Sweet, Andrew. "#beta#-adrenergic agonists and lean deposition in animals." Thesis, University of Nottingham, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292616.
Full text
9
Salazar, Degracia Anna 1991. "Mechanisms of muscle wasting in cachexia models : therapeutic implications." Doctoral thesis, Universitat Pompeu Fabra, 2019. http://hdl.handle.net/10803/666924.
Full textAbstract:
La caquexia afecta negativamente a los pacientes con enfermedades crónicas y sobre todo en el cáncer. Las estrategias terapéuticas son aún limitadas. Los beta2-agonistas (formoterol) y el soporte nutricional (L-carnitina) pueden atenuar los efectos deletéreos en el músculo. En la presente tesis, el tratamiento con formoterol y L-carnitina indujo efectos beneficiosos (peso corporal y muscular, estructura, apoptosis, proteólisis y vías de señalización) en el diafragma y músculos de las extremidades en un modelo experimental de caquexia cancerosa (hepatoma ascitico Yoshida AH-130, en ratas). En ratones con caquexia cancerosa (células de adenocarcinoma del pulmón LP07), el tratamiento del tumor con anticuerpos monoclonales (anti-PD1, anti-CTLA4, anti-CD137, y anti-CD19) indujo efectos beneficiosos de la misma índole como consecuencia de la disminución del tamaño y la carga tumoral. En esta tesis se ha demostrado que diversas vías de señalización y mecanismos implicados en la degradación proteica y muscular se ven atenuadas, mejorando las características fenotípicas y funcionales de los músculos diafragma y periféricos en respuesta a diversas estrategias terapéuticas. (165 palabras)Cachexia negatively affects patients with chronic diseases and especially in cancer. Therapeutic strategies are still limited. The beta2-agonists (formoterol) and the nutritional support (L-carnitine) can attenuate the deleterious effects in the muscle. In this thesis, treatment with formoterol and L-carnitine induced beneficial effects (total body and muscle weights, structure, apoptosis, proteolysis and signaling pathways) in the diaphragm and limb muscles in an experimental model of cancer cachexia (AH-130 Yoshida hepatoma ascites cells, in rats). In mice with cancer cachexia (LP07 lung adenocarcinoma cells), treatment of the tumor with monoclonal antibodies (anti-PD1, anti-CTLA4, anti-CD137, and anti-CD19) induced beneficial effects of the same kind as a consequence of the decrease in size and tumor burden. This thesis has shown that various signaling pathways and mechanisms involved in protein and muscle degradation are attenuated, improving the phenotypic and functional characteristics of the diaphragm and peripheral muscles in response to various therapeutic strategies. (149 words)
10
Gibson, Michael. "Characterisation of cannabinoid receptors and their ligands in isolated smooth muscle preparations." Thesis, University of Aberdeen, 2000. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU602011.
Full textAbstract:
In recent years it has been shown conclusively that at least two cannabinoid receptors, termed CB1 and CB2, exist in mammalian tissues. Previous studies using the mouse isolated vas deferens have yielded results which suggest that this tissue contains cannabinoid CB1 receptors which, when activated, can mediate inhibition of electrically-evoked contractions. However, there is evidence which indicates that several of the cannabinoid receptor agonists investigated in this study may exert their effects via non-CB, or even non- cannabinoid mechanisms. In the present study, this evidence was further investigated using the cannabinoid-mediated inhibition of electrically-evoked contractions in the mouse isolated vas deferens as a model of study. The results obtained from studies using the cannabinoid receptor antagonists O-1184 and the CB1-selective SR141716A highlighted the existence of a level of agonist-dependent antagonism in mouse isolated vas deferens. This was indicated by discrepancies obtained in the pKB values of these antagonists against the compounds under investigation. In this series of investigations it was observed that the endogenous cannabinoid receptor agonist, anandamide and the capsaicin-anandamide hybrid compound, arvanil were less potently antagonised by the CB1selective antagonist/inverse agonist, SR141716A than the highly CB1-selective agonist methanandamide. Such discrepancies in pKB values indicate that anandamide and arvanil may be acting on a receptor type distinct from the cannabinoid CB1 receptor. Additionally this series of studies indicated that anandamide and WIN55212-2 were more potently antagonised when non-cumulative responses to these compounds were constructed, indicating the possibility of tolerance developing to these compounds during the construction of cumulative concentration response curves. Several, more recent studies have indicated that anandamide and its metabolically more stable analogue methanandamide may exert their actions in part through vanilloid VR1 receptors. Upon further investigation using the vanilloid VR1 receptor antagonist capsazepine in addition to SR141716A, it was observed that the effects of anandamide, methanandamide, and the capsaicin-anandamide hybrid arvanil could be attenuated by both antagonists. These results indicate that these three agonists can act through both receptor types to mediate their effects in the mouse isolated vas deferens. In this study the putative water-soluble cannabinoid receptor agonist, O-1057 was shown to inhibit the of electrically-evoked contractions in the mouse isolated vas deferens when only water was used as a vehicle. This effect was inhibited by the cannabinoid receptor antagonists O-1184 and SR141716A, providing evidence that this novel water-soluble compound was acting through the CB1 receptor. In a further study the ability of the endogenous compound palmitoylethanolamide and a range of cannabinoids which can act on the CB2 in addition to the CB1 receptor, to downregulate mast cell degranulation was investigated. It was observed that PEA, CP55940 and WIN55212-2 but not the highly CB2 receptor-selective L759656 could exert this effect. It was not possible to investigate the effects of the CB2 receptor antagonist/inverse agonist SR144528 at this time.
11
Belkhiria, Chama. "Exploration et analyse de la relation cerveau-muscles squelettiques lors de la préparation et de l’exécution motrice." Thesis, Paris 10, 2016. http://www.theses.fr/2016PA100191.
Full textAbstract:
Les travaux de cette thèse s’inscrivent à la frontière des neurosciences et de la physiologie musculaire. Trois études se sont articulées de la préparation et l’exécution motrice. La première étude (A) a relié l'activité cérébrale à l'activité musculaire lors de la préparation motrice. Les résultats ont montré que des régions, telles que le cortex moteur primaire et l’aire motrice supplémentaire sont impliquées dans l'activité du muscle fléchisseur (FDS) alors que d’autres régions, telles que les ganglions de la base, les aires fronto-pariétales et le cervelet, sont impliquées dans l'activité du muscle extenseur (EDC). L’étude (B) a exploré le rôle du réseau cérébro-cérébelleux et du réseau striatal lors de l’exécution d’une tâche cognitive et motivationnelle. Les données ont révélé que la partie antérieure du lobule VI droit était activée par l'exécution motrice tandis que sa partie postérieure était spécifiquement activée par les encouragements verbaux. Les mesures de l’interaction psychophysiologique ont permis de faire immerger une boucle de connectivité fermée et formée par le cortex cérébral, le cervelet et les noyaux rouges. La troisième étude (C) concerne l’effet de la consigne réalisée lors de l’exécution motrice sur les paramètres neuromusculaires de FDS et EDC. Les résultats ont montré que la Force Maximale Volontaire, la Pente Maximale de Montée de Force et l’éléctromyographie associée étaient plus élevées (p < 0.05) avec la consigne accompagnée d’encouragement verbalThe present work fits on the border of neurosciences and muscular physiology. Three studies explored the brain and muscle activities following motor preparation and execution. The first study (A) linked brain and muscle activity during motor preparation. The results revealed that regions (e.g primary motor cortex and supplementary motor area) are involved in the activity of the flexor muscle (FDS) while other regions (e.g basal ganglia, fronto-parietal areas and cerebellum) are involved in the activity of the extensor muscle (EDC). The study (B) explored the role of cerebro-cerebellar and striatal networks during the execution period of cognitive and motivational task. The data showed that the anterior part of the right lobule VI was activated by the motor task, while its posterior part was specifically activated by verbal encouragement. Measurements of psychophysiological interaction revealed a closed connectivity loop formed by the cerebral cortex, the cerebellum and the red nuclei. The third study (C) concerned the effect of instruction on neuromuscular parameters of FDS and EDC muscles during motor execution. The results showed that the Maximum Voluntary Force, the Maximum Rate of Force Development and the associated electromyographic signal are the highest (p < 0.05) with cognitive, motivational and verbal encouragement condition
12
Malgoyre, Alexandra. "Déterminants mitochondriaux de l'oxydation des acides gras : modulation par l'entraînement, l'hypoxie et un agoniste PPAR-δ." Thesis, Grenoble, 2011. http://www.theses.fr/2011GRENV013/document.
Full textAbstract:
La plasticité mitochondriale à l'égard de l'oxydation de substrats, et sa participation à la transition métabolique ont été étudiées dans deux conditions: l'exposition chronique à l'hypoxie et l'entraînement en endurance, connues comme modulatrices de la préférence de substrats. Ainsi l'affinité pour le palmitoyl carnitine est augmentée par l'hypoxie et la restriction calorique alors qu'au contraire le flux maximal de palmitoyl CoA (PCoA) semble freiné par l'hypoxie. Quant aux effets de l'entraînement, malgré une amélioration du temps limite de course à intensité sous-maximale et une augmentation des capacités oxydatives globales, nous ne retrouvons pas de facilitation de l'oxydation du PCoA. Par ailleurs, on observe une augmentation des messagers PPAR-delta et d'UCP-3 en réponse à une exposition aigue à l'hypoxie. Le rôle de PPAR-delta sur la modulation de l'utilisation de substrats par la mitochondrie a aussi été envisagé en utilisant un agoniste pharmacologique de PPAR-delta, le GW 742. Celui-ci, permet d'améliorer l'efficacité catalytique du complexe enzymatique CPT-1 tout en limitant l'oxydation du pyruvate, également diminuée dans les muscles oxydatifs au cours de la restriction calorique. Le traitement par GW 742, s'il limite l'altération de l'efficacité catalytique de CPT-1 observée en hypoxie, ne permet pas de rétablir, un niveau d'oxydation en PCoA similaire à celui observé en situation contrôle. Le GW 742 s'est aussi montré capable de restaurer le flux en PCoA altéré par l'entraînement, même si la fonction du transport CPT-1 reste limitante devant l'augmentation du potentiel oxydatif induit par l'entraînement. Par ailleurs, nous n'avons pas retrouvé de relation étroite entre les variations d'affinité en PCoA et la performance aérobie sous-maximale, pourtant influencée par la capacité à oxyder préférentiellement les lipides. Enfin, la diminution du flux en pyruvate associée à l'augmentation de l'utilisation des acides gras à longue chaîne observée lors du traitement par GW 742 ou au cours de la restriction calorique pose la question du rôle joué par une cible particulière de PPAR-delta sur la mitochondrie, la protéine découplante UCP-3Substrate oxidation and its contribution to metabolic shift, as markers of muscle plasticity have been studied under two specific condition, the prolonged exposure to ambient hypoxia, and endurance training, two conditions known as leading to changes in substrate use. Our result show that the affinity for palmitoyl carnitine is increased by both hypoxia and food restriction, whereas in contrast exposure to hypoxia slow down the palmitoyl CoA (PCoA) maximal use. On the other hand, endurance training led to enhanced physical performance and increased muscular oxidative capacities, but failed to enhance PCoA oxidation. The transcripts for PPAR-delta and UCP-3 increased in response to aucte exposure to hypoxia. Moreover, we studied the role played by PPAR-delta on the substrate use modulation, using new PPAR-delta agonist known as GW 742. In the present study, this new pharmacological substance has been shown to enhance the catalytic efficiency of CPT-1 and decrease the pyruvate oxidation. Moreover, GW 742 administration limits the hypoxia-induced decrease of CPT-1 activity, but failed to recover levels of PCoA oxidation similar to those observed in control conditions. GW 742 administration was able to suppress the effects of training on maximal PCoA oxidation, even if the functional CPT-1 activity remains limiting regarding the training-induced increase in oxidative capacity. On the other hand, we failed to show strong relationship between PCoA affinity and physical performance. Finally, the concomitant increase in long chain fatty acid oxidation and decrease in pyruvate oxidation resulting from either GW 742 use or food restriction, addresses the issue of the role played by the uncoupling protein UCP-3 on mitochondrial function
13
Édouard, Pascal. "Adaptations de la force musculaire des muscles rotateurs médiaux et latéraux dans la stabilisation dynamique de l' articulation scapulo-humérale : applications à des situations pathologiques et sportives." Thesis, Saint-Etienne, 2011. http://www.theses.fr/2011STET010T/document.
Full textAbstract:
Le but de ce travail est de déterminer les liens éventuels existant entre la force et l’équilibre agoniste / antagoniste des muscles rotateurs médiaux et latéraux de l’articulation scapulohumérale, et la stabilité scapulo-humérale. La première partie de ce travail est un rappel d’anatomie fonctionnelle, de physiologie articulaire et de biomécanique de l’articulation scapulo-humérale, ainsi que des aspects pathologiques en rapport avec la problématique de sa stabilité et de son exploration. La deuxième partie propose une analyse critique de la technique d’exploration de la force musculaire par dynamométrie isocinétique, afin de déterminer un protocole d’évaluation fiable et reproductible. Ainsi, nous choisissons d’utiliser la position d’évaluation la plus reproductible et la plus adaptée pour l’évaluation de sujets pathologiques : la position assise avec 45° d’abduction dans le plan de la scapula avec correction de la gravité. La troisième partie a pour objet de rechercher, à partir d’études cliniques originales, les liens existant entre la force musculaire des rotateurs médiaux et latéraux de l’épaule et l’instabilité antérieure chronique post-traumatique d’une part, et les adaptations de cette force avec certaines sollicitations sportives d’autre part. Bien qu’un déficit de la force musculaire des rotateurs médiaux et latéraux soit associé à l’instabilité antérieure chronique, nos études ne rapportent pas d’association entre le déséquilibre agoniste/antagoniste et l’instabilité antérieure chronique. Dans le cadre de la pratique de sports sollicitant les membres supérieurs, les adaptations de la force, avec une augmentation de la force des muscles rotateurs médiaux et latéraux du côté dominant, sont inconstantes, et surtout, nos résultats ne rapportent aucun déséquilibre agoniste/antagoniste induit par la pratique sportive. En conclusion, notre travail de thèse met en évidence des adaptations de la force musculaire sans perturbation de l’équilibre agoniste/antagoniste des rotateurs médiaux et latéraux de l’articulation scapulo-humérale, associées à l’instabilité scapulo-humérale ou induites par la pratique de sports sollicitant cette articulation. Prenant en compte les limites de notre expérimentation, on peut faire l’hypothèse que les adaptations physiologiques induites par la pratique sportive n’interviendraient pas comme un mécanisme de désadaptation, ou un facteur de risque prédisposant, à l’origine des pathologies de l’articulation scapulo-humérale. Ainsi, notre conclusion serait que l’équilibre agoniste / antagoniste aurait un rôle protecteur de la stabilité articulaire ; la survenue d’un déséquilibre musculaire agoniste / antagoniste serait alors secondaire à une lésion anatomique et marquerait le signe de son évolution longue et/ou péjorativeThe aim of this work is to determine the possible links between strength and agonist/antagonist balance of the shoulder internal and external rotators muscle, and the glenohumeral stability. The first part of this work is a reminder of functional anatomy, joint physiology and biomechanics of the glenohumeral joint, and pathological aspects related to the problem of its stability and its exploration. The second part propose a critical analysis of technical exploration of muscular strength by isokinetic dynamometer to determine a reliable and reproducible protocol. We choose to use the more reliable and more suitable position for evaluation of pathological subject: the seated position with 45° of shoulder abduction in the scapular plane, with gravity corrected. The third part is aimed to research, from original clinical studies, the relationship between shoulder internal and external rotators muscle strength and balance, and shoulder instability on the one hand, and adaptations of this strength with sports practice on the other hand. Although a deficit in rotators muscle strength is associated with recurrent anterior instability, our work reporte no association between agonist/antagonist imbalance and recurrent anterior instability. In overhead sports and sports seeking the upper limbs, adaptations of strength, with a rotator strength increase on the dominant side, are inconsistent, and most importantly, our results reporte no agonist/antagonist imbalance induced by the sports practice. In conclusion, this work highlights adaptations in strength and balance of the shoulder internal and external rotators muscle associated with the glenohumeral joint instability, or induced by the sports practice. Tacking into account the limits of our experiment, we can hypothesis that any physiological adaptations induced by sport practice would not intervene as a pathophysiological mechanisms of desadaptation, or not be considered a risk factor predisposing, to glenohumeral joint diseases. Thus, our conclusion is that the agonist/antagonist balance would have a protective role of the joint stability; the occurrence of a muscle agonist / antagonist imbalance may be secondary to an anatomical lesion and mark the sign of its long and/or pejorative evolution
14
Buckler, K. J. "Actions of adrenergic agonists on transmembrane ion exchanges in skeletal and heart muscle." Thesis, University of Newcastle Upon Tyne, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380754.
Full text
15
Morris, Gavin Edward. "Mechanisms of airway smooth muscle activation by agonists of toll-like receptors." Thesis, University of Sheffield, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.425196.
Full text
16
Parr, Timothy. "Calpain proteinase mRNA and beta-agonist induced muscle growth." Thesis, University of Nottingham, 1991. http://eprints.nottingham.ac.uk/11445/.
Full textAbstract:
The mechanism by which β-agonists induce skeletal muscle hypertrophy is believed largely to be through a reduction in protein degradation. These growth promoters are also known to effect the activity of the calcium dependent proteinases (calpains) and their specific endogenous inhibitor calpastatin. The changes in activity appear to be toward a decrease in the calpain system's proteolytic potential. In this study attempts were made to determine whether the altered activity of the enzymes and inhibitor were brought about by induced changes in gene expression as reflected by altered levels of specific mRNAs. Various strategies were employed to generate oligonucleotide and cDNA probes to calpain I and II and calpastatin which would detect their respective mRNAs in L. dorsi total RNA samples originating from a bovine growth trial using the ß-agonist cimaterol. Semi-quantiative measurements of specific mRNAs using Northern blot analysis were related to enzyme and inhibitor activities. In addition ß-agonist-mediated effects on muscle RNA and expression of actin and myosin light chain 2 mRNAs were determined. Using a human calpain cDNA specific hybridization was detected for bovine calpain II mRNA which increased by 34% in the L. dorsi of cimaterol treated animals, similar to the increase in the enzyme activity, 28%. A novel bovine-specific calpastatin cDNA was generated by the polymerase chain reaction and sequence analysis allowed comparison to those already published for other species. Using this PCR cDNA as a probe multiple calpastatin mRNAs were detected in cattle L.dorsi, as had been observed in rabbit. The predominant mRNA increased by 160% in cimaterol treated steers compared to a 76% change in inhibitor activity. There changes were in contrast to the essentially unchanged response of muscle total RNA and actin and myosin light chain 2 specific mRNAs in treated animals. The implications for the calpain system in ß-agonist induced hypertrophy are discussed.
17
Gyurkovics, Gabor. "Effects of isoproterenol, an adrenergic agonist, on resting skeletal muscle." Thèse, Université de Sherbrooke, 2009. http://savoirs.usherbrooke.ca/handle/11143/4283.
Full textAbstract:
Data in this study show the effects of isoproterenol (ISO), a [bêta]-adrenergic agonist, on the total calcium content of the sarcoplasmic reticulum (SR), denoted [Ca[subscript T]][subscript SR]. Tetramethyl murexide (TMX), a membrane permeable, low affinity Ca[superscript 2+] indicator was used to monitor SR Ca[superscript 2+] content. The fraction of calcium-bound form of TMX in the SR ([f]Ca) is approximately proportional to the concentration of the free Ca[superscript 2+] in the SR ([Ca[superscript 2+]][subscript SR]) which in turn can be used to give [Ca[subscript T]][subscript SR]. Results show that 10 [mu]M ISO increases [Ca[superscript 2+]][subscript SR] by 112% in 30 min. in resting frog skeletal muscle. No significant increase was observed with no Ca[superscript 2+] present in the external solution indicating that ISO caused a Ca[superscript 2+] influx across the surface/T-system membrane. This increase in [Ca[superscript 2+]][subscript SR] occurred with an exponential delay ([tau] = 7.0 min.) and failed to reverse after washing out ISO. These results suggest that ISO stimulates the expression of a channel -permeable to calcium during resting potentials- which would remain active or open even after washing out ISO. These results argue against the involvement of most of voltage-dependent Ca[superscript 2+] channels that are gated by depolarization. Furthermore, we showed that hyperpolarization in ISO further increases Ca[superscript 2+] influx. The increase in rate of influx came on with an exponential delay ([tau] = 1.6 min.), and couldn't be explained simply by the increased driving force for Ca[superscript 2+] or by inward rectification. This delay also argues against the involvement of hyperpolarization-activated channels. The fact that the rate of Ca[superscript 2+] flux did not decrease during hyperpolarization further supports the idea that the Ca[superscript 2+] influx is not due to depolarization-activated Ca[superscript 2+] channel. In the absence of ISO, the level of [f]Ca was the same with and without Ca[superscript 2+] in the external solution, indicative of a lack of Ca[superscript 2+] influx under resting physiological conditions. When the level of [f]Ca was reduced to 30% of the physiological level with 20 mM EGTA, the average value of [f]Ca was the same with or without external Ca[superscript 2+]. These results thereby arguing against the involvement of store operated mechanisms in the regulation of SR Ca[superscript 2+] content in the physiological range. The data show two well distinguished effects when ISO was removed. One is a reversible effect which showed a sudden, transient decrease in SR calcium content (termed"dip"). The"dip" can be described with a single exponential and corresponds with the rate of Ca[superscript 2+] release observed in response to a depolarization to -70 mV. The"dip" appears to require the reversal of the SR calcium pump (SERCA). After the"dip", SR calcium content rose again and reached the same rate as was observed during ISO. This steady rise in SR calcium content appeared to be the other, irreversible effect of ISO. In addition, during the course of ISO stimulation, we observed an increase in myoplasmic pH. One possible explanation could involve the activation of [alpha]-adrenergic receptors by ISO. The receptors activate the PLC-IP3 pathway which, in turn, enhances the Na/H exchanger and thus the removal of H+ ions from the myoplasm. In summary, the data indicate that adrenergic stimulation increases [Ca[subscript T]][subscript SR] in resting fibers by activating Ca[superscript 2+] influx across the surface/T-system membrane and is consistent with the expression of an unknown Ca[superscript 2+] channel. Our results also raise doubts about whether, store-operated mechanisms are involved in fibers depleted to 30% of their normal [Ca[superscript 2+]][subscript SR]. The data also suggest that SERCA is directly enhanced by ISO.
18
Oguma, Tetsuya, Hiroaki Kume, Takayuki Ishikawa, Satoru Ito, Masashi Kondo, Haruo Honjo, Kaichiro Kamiya, and Kaoru Shimokata. "The Effect of β-adrenargic Agonists on Ca^2+ Sensitivity in Tracheal Smooth Muscle." Research Institute of Environmental Medicine, Nagoya University, 2003. http://hdl.handle.net/2237/7593.
Full text
19
Oguma, Tetsuya, Hiroaki Kume, Satoru Ito, Naoya Takeda, Haruo Honjo, Itsuo Kodama, Kaoru Shimokata, Kaichiro Kamiya, and 香一郎 神谷. "Involvement of reduced sensitivity to Ca2+ in b-adrenergic action on airway smooth muscle." Blackwell Scientific Publication, 2006. http://hdl.handle.net/2237/2750.
Full text
20
Brochart, Hervé. "Determination de l'affinite et de l'efficacite des agonistes alpha-adrenergiques par une methode fonctionnelle : application a l'etude des effets de l'endothelium." Strasbourg 1, 1987. http://www.theses.fr/1987STR10778.
Full text
21
Hari, shankar lal das Ganesh kumar. "Design, modeling and control of inherently compliant actuators with a special consideration on agonist-anthropomorphic configuration." Thesis, Toulouse, INSA, 2016. http://www.theses.fr/2016ISAT0030/document.
Full textAbstract:
Conception, modélisation et contrôle des actionneurs intrinsèquement conformes avec une considération particulière sur la configuration anthropomorphe agoniste-antagoniste "La recherche vise à la conception, la modélisation et le contrôle des actionneurs intrinsèquement conformes pour les systèmes anthropomorphes.La première partie du travail se concentre sur l'étude de divers Existants et rechercher la possibilité d'autres actionneurs autres que les moteurs électriques conventionnels.Une attention particulière est accordée aux actionneurs souples à base de polymères élctroactifs qui ont un bon potentiel dans les futures applications robotiques. Parallèlement, on a synthétisé un modèle de la dynamique de l'actionneur et du contrôleur basé sur le modèle (MPC et contrôle optimal) pour un bras anthropomorphe 7 Dofs actionné par une paire antagoniste-agoniste de Muscles Artificiels Pneumatiques (PAM) à chaque articulation. Ce modèle et contrôleur est alors intégré dans l'environnement logiciel développé par l'équipe. En utilisant le bras manipulateur anthropomorphe basé sur PAM et le simulateur numérique, des tests sont effectués afin d'évaluer le potentiel de cet actionneur et de comparer avec les capacités du corps humainDesign, modeling and control of inherently compliant actuators with a special consideration on agonist- antagonist anthropomorphic configuration" The research aims at the design, modeling and control of inherently compliant actuators for anthropomorphic systems. The first part of the work focuses on the study of various existing designs and look for the possibility of alternative actuators other than the conventional electric motors. Special attention is given to elctroactive polymer based soft actuators which have good potential in future robotic applications. In parallel, a model of the actuator dynamics and the model-based controller (MPC and optimal control) have been synthesized for an anthropomorphic 7 Dofs arm actuated by antagonist-agonist pair of Pneumatic Artificial Muscles (PAMs) at each joint. Such model and controller is then integrated within the software environment developed by the team. Using the PAMs based anthropomorphic manipulator arm and the numerical simulator, tests are done in order to evaluate the potential of this actuator and compare with the human body capabilities
22
Rajab, P. E. "The metabolic, biochemical and cardiovascular effects of treatment with clenbuterol in the rat." Thesis, University of Nottingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285682.
Full text
23
Wardle, Robert L. "Functional antagonism between muscarinic receptor and beta-adrenergic receptor agonists in equine trachealis muscle in vitro /." The Ohio State University, 1994. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487858417981441.
Full text
24
Henrionnet, Alexandra. "Déterminants mitochondriaux de l'oxydation des acides gras : modulation par l'entraînement, l'hypoxie et un agoniste PPAR-*." Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00624381.
Full textAbstract:
La plasticité mitochondriale à l'égard de l'oxydation de substrats, et sa participation à la transition métabolique ont été étudiées dans deux conditions: l'exposition chronique à l'hypoxie et l'entraînement en endurance, connues comme modulatrices de la préférence de substrats. Ainsi l'affinité pour le palmitoyl carnitine est augmentée par l'hypoxie et la restriction calorique alors qu'au contraire le flux maximal de palmitoyl CoA (PCoA) semble freiné par l'hypoxie. Quant aux effets de l'entraînement, malgré une amélioration du temps limite de course à intensité sous-maximale et une augmentation des capacités oxydatives globales, nous ne retrouvons pas de facilitation de l'oxydation du PCoA. Par ailleurs, on observe une augmentation des messagers PPAR-delta et d'UCP-3 en réponse à une exposition aigue à l'hypoxie. Le rôle de PPAR-delta sur la modulation de l'utilisation de substrats par la mitochondrie a aussi été envisagé en utilisant un agoniste pharmacologique de PPAR-delta, le GW 742. Celui-ci, permet d'améliorer l'efficacité catalytique du complexe enzymatique CPT-1 tout en limitant l'oxydation du pyruvate, également diminuée dans les muscles oxydatifs au cours de la restriction calorique. Le traitement par GW 742, s'il limite l'altération de l'efficacité catalytique de CPT-1 observée en hypoxie, ne permet pas de rétablir, un niveau d'oxydation en PCoA similaire à celui observé en situation contrôle. Le GW 742 s'est aussi montré capable de restaurer le flux en PCoA altéré par l'entraînement, même si la fonction du transport CPT-1 reste limitante devant l'augmentation du potentiel oxydatif induit par l'entraînement. Par ailleurs, nous n'avons pas retrouvé de relation étroite entre les variations d'affinité en PCoA et la performance aérobie sous-maximale, pourtant influencée par la capacité à oxyder préférentiellement les lipides. Enfin, la diminution du flux en pyruvate associée à l'augmentation de l'utilisation des acides gras à longue chaîne observée lors du traitement par GW 742 ou au cours de la restriction calorique pose la question du rôle joué par une cible particulière de PPAR-delta sur la mitochondrie, la protéine découplante UCP-3.
25
Mazon, Madeline Rezende. "Efeitos da Imunocastração e de agonistas beta-adrenérgicos sobre a qualidade da carne de bovinos." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/74/74131/tde-18052016-095207/.
Full textAbstract:
Os agonistas beta-adrenérgicos (βAA) são conhecidos por aumentar a hipertrofia muscular e lipólise, neste caso uma maneira de se reduzir o efeito da lipólise seria a imunocastração. Dessa forma, o objetivo deste projeto foi avaliar o efeito dos βAA e da imunocastração sobre a qualidade da carne de bovinos Nelore. Foram utilizados noventa e seis bovinos Nelore, sendo que metade dos animais (n=48) receberam uma dose da vacina de imunocastração, e após 30 dias receberam a segunda dose. A outra metade dos animais (n=48) não recebeu nenhuma dose da vacina. Durante 70 dias os animais foram alimentados com uma dieta padrão composta de 24% volumoso e 76% de concentrado. Após 70 dias de confinamento os animais foram divididos em três grupos, dentro de bloco (peso inicial) e condição sexual e foram alimentados por 30 dias, com umas das seguintes dietas: CON - dieta padrão utilizada na fase anterior, sem a adição de βAA; ZIL - dieta padrão acrescida de 80 mg/dia Cloridrato de Zilpaterol; RAC - dieta padrão acrescida de 300 mg/dia Cloridrato de Ractopamina. Ao final desse período os animais foram abatidos e colhidas amostras do músculo Longissimus dorsi para as avaliações de qualidade de carne, lipídeos totais, perfil de ácidos graxos, análise sensorial do consumidor, perfil morfométrico muscular, expressão dos genes calpaína e calpastatina, comprimento de sarcômero. Para a maioria das características avaliadas não foram observadas interações entre os tratamentos. Ao avaliar o efeito da condição sexual, os animais imunocastrados apresentaram maiores intensidades de cor L, a e b, lipídios totais, ácidos oleico, palmítico e total de monoinsaturados e maior frequência para as fibras oxidativas (FO) e glicolíticas (FG) em relação aos não-castrados. Contudo, os animais não-castrados tiveram uma tendência a apresentarem uma carne mais macia na análise sensorial e obtiveram maior frequência das fibras oxidativasglicolíticas (FOG) em relação aos imunocastrados. Quanto ao efeito dos βAA, o grupo ZIL apresentaram uma carne menos macia na força de cisalhamento, maiores concentrações de ácidos heptadecanoico, linoleico, araquidonico ácido C20:3 N6C8C11C14, ômega 6, maior frequência para as FO e menor para FG em comparação ao grupo RAC e CON. No entanto, os animais do grupo CON e ZIL apresentaram maior área para as FO em comparação ao grupo RAC, enquanto que para as FOG, os animais do grupo CON tiveram maior área do que os animais do grupo RAC e ZIL. Na análise sensorial, os grupos RAC e ZIL receberam menores notas para os atributos textura e qualidade global em relação ao CON. Não foi observado efeito da condição sexual e dos βAA sobre a expressão dos genes e comprimento de sarcômero. Conclui-se que a condição sexual e a suplementação com os βAA podem alterar a qualidade da carne, perfil de ácidos graxos e morfométrico muscular, sem, contudo, alterar a expressão dos genes e do comprimento de sarcômero.The Beta adrenergic agonist (βAA) are knowed for increase muscle hypertrophy and lipolysis, in this case on way for decrease the lipolysis effect is use the immunocastration. The objective of this research was evaluated the effect of βAA and immunocastration on meat quality of Nellore . Ninety-six Nellore were fed in this trial; half of the animals (n = 48) received one dose of immunocastration vaccine on d 0, and received another dose at d 30. The other half of animals (n = 48) received no vaccine. Animals were fed with a standard diet consisting of 24% forage and 76% concentrate for 70 d. After 70 d of the standard diet, animals were divided into three groups, and were fed 30 d with one of the following diets: CON - standard diet used in the previous phase, without the addition of βAA; ZIL - standard diet plus 80 mg/d Zilpaterol hydrochloride; RAC - standard diet plus 300 mg/d Ractopamine hydrochloride. After this period, animals were harvested and the Longissimus dorsi sample were colleted to evaluate meat quality, total lipid content, fatty acid profile, consumer sensory analysis, muscle morfometric profile, genes expression of calpain and calpastatin and sarcomere length. For almost of characteristics evaluated, were not observed interactions between treatments. The effect of sexual condition, imunocastrated animals showed higher intensity of color L, a and b, total lipidics, oleic, palmitic and total monounsaturated acids and more frequency for oxidative fibers (FO) and glycolytic fibers (FG) in relation at noncastrated. However, non-castrated animals had a tendency to show a meat tender in sensory analysis and more frequency of oxidative-glicolytics fibres (FOG) in relation to imunocastrated. The βAA effect, ZIL group showed a meat less tender, higher concentrations of heptadecanoic, linoleic, araquidic acids, C20:3 N6C8C11C14, ômega 6, higher frequency for FO and less for FG than RAC and CON group. Animals of CON and ZIL group showed more FO area than RAC group, while for the FOG, animals from COM group showed more area than animals from RAC and ZIL group. In the sensory analysis, RAC and ZIL group received lower grades for tenderness and global quality in relation to COM group. Was no observed effect of sexual condition and βAA for genes expressions and sarcomere length. As conclusion, sexual condition and βAA affected the meat quality, fatty acid profile, muscle fibers, but not affect genes expression and sarcomere lenght.
26
Apolinar, Sanrda. "BK channel involvement in beta-adrenergic relaxation of murine tracheal smooth muscle a thesis /." San Antonio : UTHSC, 2008. http://learningobjects.library.uthscsa.edu/cdm4/item_viewer.php?CISOROOT=/theses&CISOPTR=32&CISOBOX=1&REC=3.
Full text
27
Braxton, Joi Requan. "Effect of preload on the response of mouse trachea smooth muscle to cholinergic stimulation a thesis /." San Antonio : UTHSC, 2008. http://learningobjects.library.uthscsa.edu/cdm4/item_viewer.php?CISOROOT=/theses&CISOPTR=33&CISOBOX=1&REC=10.
Full text
28
Miller, Christian. "Effets comparés de deux modalités d'entraînement sur le développement de la force musculaire : électrostimulation et contraction volontaire." Paris 11, 1989. http://www.theses.fr/1989PA112382.
Full textAbstract:
Le but de ce travail est de préciser les possibilités d'adaptations physiologiques du muscle soumis à un entraînement visant à l'amélioration de la force maximale. Deux modalités d'entraînement isométrique monoangulaire sont pratiquées : l'une sous électrostimulation (ES) l'autre en contraction volontaire (CV). Leurs effets respectifs sur les caractéristiques de la relation Couple-Angle de flexion du coude et de l'activité électromyographique des principaux agonistes et antagonistes sont comparés. Des augmentations significatives de la force sont observées après ES comme après CV. Les deux modes d'entraînement aboutissent à des résultats équivalents si les niveaux de couple externe exercés pendant l'entraînement sont identiques. En outre, l'amélioration de la force se révèle spécifique de l'angle entraîné. Elle est accompagnée d'une élévation du niveau d'activation maximale des muscles agonistes associée à une stabilité de l'activité myoélectrique des antagonistes, quel que soit le mode d'entraînement. L'existence d'une adaptation d'ordre neurophysiologique impliquant une meilleure activation du pool de motoneurones des fléchisseurs semble être à l'origine des gains de force observés. Ce mécanisme d'adaptation qui apparaît après ES et après CV semble régulé par l'intensité du couple externe exercé pendant l'entraînement. Le rôle déterminant que pourrait jouer une modification de l'efficacité des muscles posturaux dans le processus d'amélioration de la force maximale est ici suggéréThe purpose of this study was to examine some physiological muscle adaptations to strengthening. The effects of monoangular isometric strength training using Electrical Stimulation (ES) or Voluntary Contraction (CV) upon the Torque-Length relationship and the electromyographic activity of the agonist and antagonist muscles were compared. Maximum Voluntary Isometric Force was significantly increased beth by electrical stimulation and voluntary contraction. The two training modes yielded similar results when the electrically evoked torque and the isometric flexion torque exerced on the ergometric device, along the training sessions were equal. In this way, the increase of voluntary strength was specific to the training angle with beth training procedures. Moreover some electromyagraphic evidence was revealed with ES and CV training indicating a greater increase in the motor unit activation of the agonist at the training. So that, a neural adaptation to training seems to be unavoidable even with electrical stimulation training. This neural mechanism would be driven by the level of the isometric torque exerced on the ergometric device. We emphasize the rôle of the postural muscle in the process of strength development
29
Spring, Cécile. "Modification of spontaneous motility of smooth muscle preparations from the bovine abomasal antrum by different serotinin receptor agonists /." [S.l.] : [s.n.], 2002. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
Full text
30
Koenig, Alexander C. "Simulation of agonist and antagonist muscle activation patterns in bidirectional postural perturbation in cats." Thesis, Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/11576.
Full textAbstract:
We studied the effects of varying perturbation magnitude and direction on the postural control process of the central nervous system (CNS) caused by perturbation, before and after sensory loss. The electromyogram (EMG) response to a postural perturbation can be composed by a weighted sum of the center of mass (CoM) kinematics. We extended an existing CoM feedback model which predicted EMG of one muscle for unidirectional perturbations; we used recorded data of bidirectional perturbations, which caused muscle activity in anterior as well as posterior muscles. Modeling the CNS as two delayed feedback controllers, we reconstructed the EMGs of two antagonistic muscles simultaneously that were recorded during postural perturbation experiments on cats. Minimizing the error between predicted and recorded EMG and CoM kinematics, we were able to identify controller gains that would result in the best prediction of the recorded EMGs.
We hypothesized that the weights on the CoM kinematics remained constant independent of variations in perturbation magnitude or reversed perturbation direction. We applied our model to data from bidirectional perturbations with varying magnitude, with which the cats were perturbed for a short time in one direction and a longer time in the opposite direction.
The gains showed small variation for EMG predictions following long perturbations; however, the prediction of EMG following the initial displacement resulted in large gain variations. We showed that these variations were caused by our optimization methods, which was not able to consistently identify controller gains for short initial movements. Using the weights identified for unidirectional perturbations, we were able to predict muscle activity for both directions with the same gains. This suggests that the weights of the CoM kinematics for each muscle did not change for varying perturbation magnitude. We conclude that varying EMG shapes were induced solely by the variation of the CoM kinematics.
We repeated the investigations on data that was recorded from cats suffering from sensory loss and found reduced CoM acceleration feedback.
31
Koenig, Alexander C. "Simulation of agonist and antagonist muscle activation paterns in bidirectional postural perturbatio in cats." Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-07062006-182937/.
Full text
32
Lortie, Michel B. "The rainbow trout muscle beta(2)-adrenoceptor system: Impact of beta(2)-agonist feeding." Thesis, University of Ottawa (Canada), 2002. http://hdl.handle.net/10393/6268.
Full textAbstract:
Previous studies showed that beta2-adrenergic agonists (beta 2-AAs) enhanced muscle growth and reduced lipid deposition in animals of agricultural and economical importance, including teleost fish. The goal of the present study was to provide a mechanistic explanation underlying the reported beta2-AA-induced muscle growth in the rainbow trout (Oncorhynchus mykiss). Using radioligand binding assays and adenylyl cyclase/cAMP assays, this study characterized and demonstrated the presence of functional beta2-adrenoceptors (beta2-ARs) on red and white muscle membranes. Trout fed 40 ppm of two beta2-AAs (clenbuterol and ractopamine) for 30 days showed no significant changes in measured body and physiological parameters, beta2-AR numbers or beta2-AR mRNA levels in red or white muscle. However, treatments significantly increased fractional protein synthesis rates in red and white muscle. These studies demonstrate that beta2-AAs impact muscle protein synthesis by mechanisms initiated at the muscle membrane beta 2-AR and include the beta2-AR-signalling pathway in a teleost fish.
33
Silva, Lucila Hernandes da. "Efeito do agonista b2-adrenérgico formoterol na regeneração muscular de ratos idosos." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/42/42131/tde-24072012-100623/.
Full textAbstract:
Músculos esqueléticos de ratos idosos apresentam uma reduzida capacidade de se regenerar após lesão. No presente estudo, nós lançamos a hipótese de que a estimulação farmacológica de adrenoceptores b2 em músculos de ratos idosos lesados poderia melhorar a regeneração destes. Ratos jovens e idosos foram tratados com injeção subcutânea do agonista b2-adrenérgico formoterol (2 mg/kg/dia) durante 10 e 21 dias após lesão do músculo sóleo. Os músculos de ratos idosos lesados e tratados com formoterol por 10 e 21 dias apresentaram menor processo inflamatório e fibras musculares em regeneração com maior calibre quando comparados aos músculos apenas lesados. O tratamento com formoterol preveniu a queda da força tetânica e aumentou a síntese de proteínas e a fosforilação de mTOR em músculos de ratos idosos lesados e avaliados após 10 dias. Nossos resultados sugerem que o formoterol melhora a capacidade regenerativa estrutural e funcional dos músculos esqueléticos de ratos idosos, e que esse efeito é mediado pelo aumento da síntese protéica através da ativação de mTOR.Skeletal muscles from old rats fail to completely regenerate following injury. In the present work, we hypothesized that pharmacological stimulation of b2-adrenoceptors in aged muscles following injury could improve their regenerative capacity. Young and aged rats were treated with a subcutaneous injection of b2-adrenergic agonist formoterol (2 mg/kg/day) up to 10 and 21 days after soleus muscle injury. Formoterol-treated muscles from old rats evaluated at 10 and 21 days post-injury showed reduced inflammation and regenerating myofibers of greater caliber when compared to their injured controls. Formoterol minimized the decrease in tetanic force and increased protein synthesis and mTOR phosphorylation in old muscles at 10 days post-injury. Our results suggest that formoterol improves structural and functional regenerative capacity of regenerating skeletal muscles from aged rats by increasing protein synthesis via mTOR activation.
34
Blackman, Sarah Kathryn. "Contribution of Calcium Entry through Non-Voltage Operated Calcium Channels to the Contractile Response of Vascular Smooth Muscle to Agonists." Thesis, King's College London (University of London), 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.487202.
Full textAbstract:
Depletion of Ca2+ stores in the sarcoplasmic reticulum results in the opening of store operated cation channels (SOCCs) on the plasma membrane, allowing Ca2 + influx into the cell and refilling of the stores. The work described in this thesis set out to determine the extent to which Ca2 + entry through the store operated pathway contributes to agonist-induced contraction. in aortic smooth mUSfle. Three major techniques were used to study agonist responses in aortae from C57BL6 mice and Wistar rats. Aortic rings were mounted in organ baths to study the pharmacology of contractile responses to noradrenaline (NA), phenylephrine (PE) thapsigargin (Tg), arg-vasopressin (AVP) and potassium chloride (KCI). These whole tissue experiments were supplemented with electrophysiological and Fura-2 microfluorimetry recordings of cells isolated from the whole tissue by enzymatic digestion. Mouse aortic ring experiments revealed that contraction in response to NA is dependent on verapamil-insensitive ion channels that can be distinguished from those activated by store depletion with Tg by their sensitivity to l-lOmM GdCh or LaCL3 • The ability of low concentrations of 2-APB to enhance contraction induced by NA suggests a role for STTh11 in mediating contraction to NA in the mouse aorta. Single cell experiments designed to further investigate SOCCs in the mouse aorta confirmed the· presence of a Ca2 +-activated chloride channel but did not confirm the presence of the SOCC reported by Trepakova et al (2001) . . Rat aortic ring experiments were carried out to investigate the role of nitric oxide (NO) in the reciprocal regulation model of receptor and store operated calcium entry. No evidence was obtained for the involvement of smooth muscle NO in modulating contractions induced by phenylephrine or AVP in whole tissues.
35
Tanfin, Zahra. "Régulation du système générateur d'AMPc dans le muscle utérin stimulation et désensibilisation par les agonistes bêta-adrénergiques et les prostaglandines : altérations associés à la gestation /." Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb376101403.
Full text
36
Tanfin, Zahra. "Régulation du système générateur d'AMPc dans le muscle utérin : stimulation et désensibilisation par les agonistes bêta-adrénergiques et les prostaglandines : altérations associées à la gestation." Paris 11, 1987. http://www.theses.fr/1987PA112216.
Full textAbstract:
Dans le myomètre de rate sous effet oestradiol, le système adénalyte cyclasique est stimulé par l'isoprotérénol (ISO), les prostaglandines (PGE2, PGI2) ainsi que par la cholératoxine (CTX) et la forskoline Cette dernière potentialise l'effet des autres effecteurs. Les stimulations dues à l'ISO et à PGE2 ne sont que transitoires : après un contact prolongé, il se 2 développe un état réfractaire. Dans les temps courts, la désensibilisation est homologue puis s'installe la désensibilisation hétérologue. La désensibilisation homologue induite par l'ISO s’accompagne d'une perte de récepteurs et un découplage partiel des récepteurs résiduels. La désensibilisation hétérologue est médiée par l'AMPc et se situe à une étape post-récepteur. Les récepteurs aux prostaglandines, contrairement aux bêta-adrénergiques, sont sous le contrôle des microtubules aussi bien pour la stimulation que pour la désensibilisation. Lors de la désensibilisation hétérologue (PGE2 → ISO), la réponse AMPc due à l'ISO est altérée alors que son effet relaxant est inchangé ; le rôle non exclusif de l'AMPc dans la relaxation bêta-adrénergique est ainsi confirmé. La gestation coïncide avec une perte générale de toutes les stimulations du système adénylate cyclasique. Cette perte est maximale à mi-gestation. L'altération de la réponse bêta-adrénergique n'est due ni à une perte de récepteurs, ni à un découplage de ceux-ci. La deuxième moitié de la gestation se caractérise par une récupération progressive de toutes les stimulations excepté celles des prostaglandines. Il ne s'agit pas d'une désensibilisation homologue due à la synthèse accrue des prostaglandines. En revanche, les prostaglandines exercent un effet inhibiteur sur la réponse AMPc induite par l'ISO. Cet effet des prostaglandines est empêché par la pertussis toxine (IAP), ce qui met en évidence l'implication du Gi. Le traitement des myomètre à mi-gestation par l'IAP restaure la réponse bêta-adrénergique et celle de CTX. L'étude quantitative de protéines "G" a montré une augmentation du rapport Gi/Gs à mi-gestation. Ainsi différents états de la gestation, caractérisés par des variations importantes d'imprégnations hormonales, sont associés d'une part à un changement de la stoéchiométrie de Gi/Gs, et d'autre part à la conversion des récepteurs aux prostaglandines (stimulation + inhibition).
37
Parsons, Sarah Jane Wilde. "A study of the pathways mediating agonist-stimulated contraction and endothelium-dependent relaxation of vascular smooth muscle." Thesis, University of Bristol, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388114.
Full text
38
Kirillova, Irina [Verfasser]. "Mechano- and thermosensitivity of muscle afferents 4 hours to 7 days after nerve injury and their responsiveness to TRP agonists / Irina Kirillova." Kiel : Universitätsbibliothek Kiel, 2012. http://d-nb.info/1063668808/34.
Full text
39
Steinert, Joern Rudolf. "Dysfunction of human vascular endothelial and smooth muscle cells in pre eclampsia : altered calcium signalling in response to agonists and fatty acids." Thesis, King's College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251598.
Full text
40
Edouard, Pascal. "Adaptations de la force musculaire des muscles rotateurs médiaux et latéraux dans la stabilisation dynamique de l' articulation scapulo-humérale : applications à des situations pathologiques et sportives." Phd thesis, Université Jean Monnet - Saint-Etienne, 2011. http://tel.archives-ouvertes.fr/tel-00718892.
Full textAbstract:
Le but de ce travail est de déterminer les liens éventuels existant entre la force et l'équilibre agoniste / antagoniste des muscles rotateurs médiaux et latéraux de l'articulation scapulohumérale, et la stabilité scapulo-humérale. La première partie de ce travail est un rappel d'anatomie fonctionnelle, de physiologie articulaire et de biomécanique de l'articulation scapulo-humérale, ainsi que des aspects pathologiques en rapport avec la problématique de sa stabilité et de son exploration. La deuxième partie propose une analyse critique de la technique d'exploration de la force musculaire par dynamométrie isocinétique, afin de déterminer un protocole d'évaluation fiable et reproductible. Ainsi, nous choisissons d'utiliser la position d'évaluation la plus reproductible et la plus adaptée pour l'évaluation de sujets pathologiques : la position assise avec 45° d'abduction dans le plan de la scapula avec correction de la gravité. La troisième partie a pour objet de rechercher, à partir d'études cliniques originales, les liens existant entre la force musculaire des rotateurs médiaux et latéraux de l'épaule et l'instabilité antérieure chronique post-traumatique d'une part, et les adaptations de cette force avec certaines sollicitations sportives d'autre part. Bien qu'un déficit de la force musculaire des rotateurs médiaux et latéraux soit associé à l'instabilité antérieure chronique, nos études ne rapportent pas d'association entre le déséquilibre agoniste/antagoniste et l'instabilité antérieure chronique. Dans le cadre de la pratique de sports sollicitant les membres supérieurs, les adaptations de la force, avec une augmentation de la force des muscles rotateurs médiaux et latéraux du côté dominant, sont inconstantes, et surtout, nos résultats ne rapportent aucun déséquilibre agoniste/antagoniste induit par la pratique sportive. En conclusion, notre travail de thèse met en évidence des adaptations de la force musculaire sans perturbation de l'équilibre agoniste/antagoniste des rotateurs médiaux et latéraux de l'articulation scapulo-humérale, associées à l'instabilité scapulo-humérale ou induites par la pratique de sports sollicitant cette articulation. Prenant en compte les limites de notre expérimentation, on peut faire l'hypothèse que les adaptations physiologiques induites par la pratique sportive n'interviendraient pas comme un mécanisme de désadaptation, ou un facteur de risque prédisposant, à l'origine des pathologies de l'articulation scapulo-humérale. Ainsi, notre conclusion serait que l'équilibre agoniste / antagoniste aurait un rôle protecteur de la stabilité articulaire ; la survenue d'un déséquilibre musculaire agoniste / antagoniste serait alors secondaire à une lésion anatomique et marquerait le signe de son évolution longue et/ou péjorative
41
Ngala, Robert A. "Regulation of glucose uptake in skeletal muscle by β-adrenoceptor agonists and antagonists and interaction with peroxisome proliferator-activated receptors α and δ." Thesis, University of Buckingham, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.429700.
Full text
42
Adams, David. "Modulation of agonist-stimulated second messenger and contractile events in bovine tracheal smooth muscle with cyclic nucleotide PDE inhibitors." Thesis, University of Leicester, 1994. http://hdl.handle.net/2381/33624.
Full textAbstract:
The aim of this thesis was to investigate and characterize the effects of isoenzyme- selective phosphodiesterase (PDE) inhibitors on a range of biochemical and functional parameters in bovine airway smooth muscle in order to further our understanding of 'cross-talk' between different second messenger pathways in this tissue. Cyclic nucleotide levels were measured after selective or non-selective PDE isoenzyme inhibition under conditions of basal and stimulated adenylyl and guanylyl cyclase activity. These data led to the conclusion that PDE IV plays an important role in the regulation of agonist-stimulated increases in cAMP levels, since under conditions of isoprenaline stimulation, incubation with the PDE IV-selective inhibitor rolipram resulted in an increase in cAMP from a control level of 20 2.7 to 50.3 4.0 pmol/mg protein. This response was potentiated in a synergistic manner by simultaneously inhibiting PDE III with ORG 9935. Co-inhibition of PDE III/IV also resulted in a significant increase in basal cAMP levels in tracheal smooth muscle slices and a marked decrease in the rolipram EC50 for cAMP accumulation in isoprenaline-stimulated slices from 205 102 to 7.3 3.0 muM. This suggested that metabolism of cAMP by PDE III is also functionally important in this tissue at least when PDE IV activity is compromized. Evidence was also obtained to suggest that cGMP is metabolized by PDE V, since incubation with zaprinast resulted in a 47% increase in basal cGMP values; however, where cGMP levels were elevated a greater increase in cGMP accumulation was seen in the presence of the nonspecific PDE inhibitor, IBMX (24.3 1.6 pmol/mg protein) compared to that seen with zaprinast (15.2 1.6 pmol/mg protein) suggesting that cGMP metabolism by other PDEs plays a significant role under these conditions. The effects of selective PDE inhibition on agonist-stimulated inositol phosphate accumulation was then investigated. Stimulation with maximally-effective concentrations of carbachol and histamine for 30 min resulted in 36- and 10-fold increases in inositol phosphate accumulations. The response to carbachol (1-100 muM) was largely unaffected by increases in cAMP accumulation caused by isoprenaline or PDE inhibition, however both manipulations inhibited the response to histamine (100muM) by approximately 80%. Again the inhibitory effects of rolipram were potentiated by ORG 9935 such that the EC50 value for rolipram-mediated inhibition was decreased from 120 27 to 1.5 0.9 muM. Such results suggest that PDE III/IV inhibition may be effective in relaxing airway smooth muscle. Consequently it was established that whilst rolipram could inhibit smooth muscle contraction stimulated by histamine or sub-maximal concentrations of methacholine, co-inhibition of PDEs with rolipram and ORG 9935 resulted in a much more potent anti-spasmogenic action. Furthermore, in contrast with the effects of rolipram alone the PDE III/IV inhibitor combination also significantly inhibited phasic contractions generated by either agonist. For example rolipram/ORG 9935 completely abolished the ability of 30uM histamine to cause a phasic contractile response. In common with previous suggestions that the membrane hyperpolarizing actions of cAMP-elevating agents may be responsible, at least in part, for the relaxation of trachealis muscle, experiments reported here suggest that PDE inhibition causes membrane hyperpolarization, possibly through increasing the open-state probability of the high- conductance, calcium-activated potassium channel, and this action may account for the mechanism whereby selective PDE inhibitors can inhibit phosphoinositide turnover and possibly as a consequence relax airway smooth muscle.
43
Aoki, Fabio Gava. "Modelos matemáticos aplicados na avaliação da mecânica respiratória em camundongos com desafios de agonista da musculatura lisa." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/3/3142/tde-01082013-153108/.
Full textAbstract:
Modelos matemáticos são utilizados como ferramentas na avaliação da mecânica respiratória para a compreensão da fisiologia e patologias do sistema respiratório. A presente pesquisa visou avaliar, através da aplicação de modelos matemáticos, a mecânica respiratória em camundongos submetidos à metacolina. Deu-se ênfase no modelo linear de compartimento único e suas variantes não lineares. Camundongos C57BL/6 (n = 8) foram traqueostomizados, ventilados mecanicamente (flexiVent, SCIREQ, Canadá) e perturbações em volume foram aplicadas para a modelagem do sistema respiratório. O protocolo experimental foi elaborado de forma a se analisar a variação dos parâmetros respiratórios durante a aplicação do agente broncoativo e também se verificou a divisão do sinal quasi-senoidal em expirações e inspirações durante a técnica de oscilação forçada (FOT) com perturbação de frequência 2,5 Hz. Com base nisso, uma rotina computacional própria foi desenvolvida para a análise dos experimentos realizados no ventilador mecânico e foram pesquisadas as vantagens e desvantagens dos modelos matemáticos aplicados. Os resultados demonstraram um aumento no desvio padrão dos parâmetros do modelo linear unicompartimental e suas variantes não lineares após a aplicação do broncoconstritor. Acredita-se que esta grande variação nos parâmetros esteja relacionada com o enrijecimento do parênquima e da heterogeneidade da ventilação pulmonar após a utilização da droga. Devido à correlação dos parâmetros do modelo com a fisiologia ocorrer somente no modelo linear, acredita-se que este ainda é o mais indicado na avaliação da mecânica respiratória e as variantes não lineares seriam indicadas como opção em casos onde o modelo linear é incapaz de realizar ajustes adequados ou para informações complementares.Mathematical models are used as tools in the assessment of respiratory mechanics for the understanding of the physiology and pathologies of the respiratory system. This study aimed to assess the respiratory mechanics by applying mathematical models in mice subjected to challenges with methacholine. Emphasis was placed on linear single-compartment model and its nonlinear variants. C57BL/6 mice (n = 8) were tracheostomized, mechanically ventilated (flexiVent, SCIREQ, Canada) and disturbances in volume were applied to the modeling of the respiratory system. The experimental protocol was developed in order to analyze the variation of respiratory parameters during the application of the bronchoactive agent. The division of quasisinusoidal signal in expirations and inspirations during the forced oscillation technique (FOT) with frequency perturbation of 2.5 Hz was also observed. Based on that, a proper computational routine was developed in order to analyze the experiments in the mechanical ventilator and the advantages and disadvantages of the applied mathematical models. The results demonstrated an increase in the standard deviation of the linear single-compartment model and its nonlinear variants parameters after the application of bronchoconstrictor. It is believed that this large variation in the parameters relates to the parenchyma stiffening and to the heterogeneity of pulmonary ventilation after the use of the drug. Due to the fact that the correlation between the model parameters and the physiology occurred only in the linear model, it is believed that this is still the most suitable model in the assessment of respiratory mechanics. Nonlinear variations of the single-compartment model would be indicated only as an option, for example, in cases where the linear model is incapable of performing appropriate fits or when additional information about the respiratory system is required.
44
Jindarat, Sarawut. "The role of TNFa and IFNy on CXCL10 regulation and beta-2 agonist inhibition in human airway smooth muscle cells." Thesis, University of Nottingham, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.537793.
Full text
45
Baxa, Timothy John. "Effect of Zilpaterol hydrochloride and steroid implantation on yearling steer feedlot performance, carcass characteristics, and skeletal muscle gene expression." Thesis, Manhattan, Kan. : Kansas State University, 2008. http://hdl.handle.net/2097/936.
Full text
46
Boas, Vanessa Fonseca Vilas. "Efeito da triiodotironina (T3) e do agonista TRb seletivo GC-24 sobre o trofismo muscular esquelético de ratos: aspectos envolvendo a proteólise dependente de proteassoma." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/42/42134/tde-08092008-153817/.
Full textAbstract:
O objetivo deste estudo foi investigar os efeitos do T3 e do seu análogo GC-24, agonista TRb seletivo, na proteólise muscular mediada pela via ubiquitina-proteassoma. Avaliamos o efeito do T3 e GC-24 no trofismo radial de fibras musculares, no nível de ubiquitinação e na expressão de genes envolvidos na via ubiquitina-proteassoma. Para tanto foram utilizados, ratos Wistar divididos em 4 grupos (Controle, 12 horas, 1 e 7 dias) e tratados com T3 e GC-24. Determinou-se a área de secção transversa dos cortes histológicos através do programa \"Image Pro-Plus\". O nível de ubiquitinação foi determinado através de Western Blot para proteína ubiquitinada e a expressão gênica por PCR em Tempo real. T3 e GC-24 promoveram redução do diâmetro das fibras musculares e aumentaram o nível de proteínas ubiquitinadas em ambos os músculos. Com relação à expressão gênica, T3 e GC-24 modularam a expressão dos genes analisados de maneira diferenciada, demonstrando que GC-24 é capaz de modular genes pouco ou não responsivos ao T3.Triiodothyronine (T3) is known to play a key role in the function of several tissues/organs via the thyroid hormone receptor isoforms a/pha (TRa) and beta (TRI3). Abnormalities in skeletal muscle function have been associated with increased leveis of T3, which is a major sarcopenia (Ioss of sarcomeres). Although the phenomenon of sarcopenia induced by T3 has been widely reported, little is known about the molecular mechanisms invo/ved in proteolysis induced by T3. In this study we have investigated the effects of T3 and GC-24, a novel synthetic TRI3¬selective compound, on the ubiquitin proteasome pathway. We analyzed the effect of T3 and GC-24 on the radial trophism, ubiquitination leveis and gene expression of the ubiquitin-proteasome pathway, which are important regulators of muscle proteolysis in the skeletal muscle. We have addressed the ubiquitin ligases (Atrogin¬1, MuRF-1 and E3a) and the deubiquitinating enzymes (UBP45, UBP69 and USP28). Wistar male rats (170-200g) were divided in 4 groups (Control, 12, 1 and 7 days). Rats received T3 (30l-\'g/100g) and GC-24 (16 I-\'g/1 OOg). After decapitation, EDL and soleus muscles were removed for histological ana/ysis, protein expression and gene expression. Cross sectional area was determined in histological sections through the software \"Image-Pro Plus. The ubiquitination leveis was determined by Western Blot and gene expression determined by Real Time PCR analysis. T3 and GC-24 reduced the diameter of the muscle fibers vs control group. Both T3 and GC-24 incresed the ubiquitination leveis, in the soleus and EDL. Regarding gene expression analysis, T3 and GC-24 modulate the gene expression in a differential manner. In the soleus, T3 increased Atrogin-1 and E3 alpha gene expression, while did not alter Murf-1 gene expression. On the other hand, in EDL Atrogin-1 gene expression is not altered, while E3 alpha and Murf-1 are elevated by T3. In the soleus and EDL deubiquitinating gene expression is mostly not altered, exception made for UBP 45, which is reduced by T3 in soleus muscle. GC-24, increased gene expression of E3a and MuRF-1 in the soleus, while did not alter Atrogin-1 gene expression. However, in EDL muscle, GC-24 increased Atrogin-1 and E3a mRNA, while did not alter MuRF-1. Finally, GC-24 decreased UBP 45 gene expression in EDL muscle and USP 28 gene expression was robustly elevated by GC-24 in both muscles analyzed. This data shows that GC-24 is able to strongly modulate genes that are less responsive or even unresponsive to T3, pointing that the GC-24-TRb complex might trans-activate differently target genes. However, both T3 and GC-24 are able to modulate the muscle proteolysis.
47
Almeida, Vivian Vezzoni de. "Respostas produtivas e expressão gênica induzidas por períodos de fornecimento de ractopamina para suínos em terminação." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/11/11139/tde-29102012-104431/.
Full textAbstract:
O agonista beta-adrenérgico ractopamina (RAC) modifica a composição da carcaça suína por aumentar a massa muscular e reduzir a deposição de gordura. O objetivo neste estudo foi avaliar os efeitos do tempo de fornecimento de RAC sobre o desempenho, concentração de ureia plasmática (CUP), características de carcaça e expressão gênica dos receptores beta- adrenérgicos (beta-AR) e das isoformas da cadeia pesada de miosina (MyHC) em suínos em terminação. Oitenta suínos, machos castrados (PV inicial = 69,42 ± 1,24 kg), foram utilizados em um experimento em blocos completos casualizados com cinco tratamentos, oito repetições por tratamento e dois animais por unidade experimental (baia). Os tratamentos consistiram de rações sem RAC (controle) ou com 10 ppm de RAC fornecidas por 7, 14, 21 ou 28 dias préabate. O PV individual e o consumo de ração por baia foram obtidos para determinar o ganho diário de peso (GDP), o consumo diário de ração (CDR) e a conversão alimentar (CA). Amostras de sangue foram coletadas para determinação da CUP. No final do experimento, os animais (PV final = 102,46 ± 1,44 kg) foram abatidos e amostras de pelos e do músculo Longissimus dorsi coletadas. As carcaças foram avaliadas 24 horas post-mortem. As amostras de pelos foram utilizadas para detecção da mutação no gene do receptor de rianodina do tipo 1 (RYR1). A expressão gênica dos beta-AR (subtipos beta1 e beta2) e das isoformas MyHC (I, IIa, IIx/d e IIb) foi quantificada nas amostras de músculo. As análises estatísticas foram realizadas apenas com os animais homozigotos dominantes para a mutação no gene do RYR1. O aumento no período de fornecimento de RAC não afetou (P > 0,05) o PV final, o GDP e o CDR, porém resultou em melhora linear (P < 0,01) na CA. Melhoras (P < 0,05) nas médias semanais de GDP e CA foram observadas durante os primeiros 21 dias de fornecimento de RAC, no entanto, o crescimento animal declinou (P < 0,05) na 4ª semana de tratamento. A CUP apresentou efeito quadrático (P < 0,01) com o aumento na duração do fornecimento de RAC. Houve aumento linear (P <= 0,01) no peso da carcaça quente, na profundidade do músculo Longissimus dorsi, na área de olho de lombo e na relação carne:gordura com o aumento na duração do tratamento com RAC. Não foram detectados efeitos da RAC (P > 0,05) sobre a expressão gênica dos beta1-AR e das isoformas MyHC IIa e MyHC IIx/d, porém o aumento no período de fornecimento de RAC tendeu a reduzir linearmente (P = 0,08) a expressão gênica dos beta2-AR. Embora os níveis de RNAm da isoforma MyHC I tenham sido reduzidos linearmente (P < 0,01), a expressão gênica da isoforma MyHC IIb aumentou linearmente (P < 0,01) com o aumento na duração do tratamento com RAC. Portanto, as melhores respostas de desempenho e carcaça ocorreram quando a RAC foi fornecida por 21 e 28 dias, respectivamente. Além disso, o agonista alterou a expressão gênica das isoformas MyHC, e é possível que a ação da RAC esteja relacionada com a população de beta2-AR.The beta-adrenergic agonist ractopamine (RAC) modifies the swine carcass composition by increasing muscle mass and decreasing fat deposition. The objective in this study was to evaluate the effects of RAC feeding duration on performance, plasma urea nitrogen (PUN) concentration, carcass traits, and gene expression of beta-adrenergic receptors (beta-AR) and myosin heavy chain (MyHC) isoforms in finishing pigs. Eighty barrows (initial BW = 69.42 ± 1.24 kg) were used in a randomized complete block design experiment with five treatments, eight replicates per treatment, and two animals per experimental unit (pen). The dietary treatments consisted of diets containing no RAC (control) or 10 ppm RAC fed for 7, 14, 21, or 28 days before slaughter. Individual pig BW and pen feed disappearance were obtained to determine average daily gain (ADG), average daily feed intake (ADFI), and feed to gain ratio (F:G). Blood samples were collected for determination of PUN concentrations. At the end of the experiment, pigs (final BW = 102.46 ± 1.44 kg) were slaughtered and hair and Longissimus dorsi muscle samples collected. The carcasses were evaluated 24 hours postmortem. Hair samples were used to detect the mutation of the ryanodine receptor type 1 (RYR1) gene. Gene expression of beta-AR (beta1- and beta2-subtypes) and MyHC isoforms (I, IIa, IIx/d, and IIb) was quantified in the muscle samples. Statistical analyses were performed using only the homozygous dominant pigs for the RYR1 gene mutation. Increasing RAC feeding period did not affect (P > 0.05) final BW, ADG, and ADFI, but resulted in a linear improvement (P < 0.01) in F:G. Average weekly improvements (P < 0.05) in ADG and F:G were observed during the first 21 days of RAC feeding, however, animal growth declined (P < 0.05) in the 4th week of treatment. The PUN concentrations showed a quadratic effect (P < 0.01) as RAC feeding duration increased. There were linear increases (P <= 0.01) in hot carcass weight, Longissimus dorsi muscle depth, loin eye area, and muscle to fat ratio as RAC treatment duration increased. No effects of RAC feeding (P > 0.05) were detected for beta1-AR and for isoforms of MyHC IIa and MyHC IIx/d gene expression, but increasing RAC feeding period tended to linearly decrease (P = 0.08) beta2-AR gene expression. Even though mRNA levels of MyHC I isoform decreased linearly (P < 0.01), gene expression of MyHC IIb isoform increased linearly (P < 0.01) as RAC treatment duration increased. Therefore, greater growth and carcass responses occurred when RAC was fed for 21 and 28 days, respectively. Furthermore, the agonist altered the MyHC gene expression and the RAC action may be related to the beta2-AR population.
48
Tantama, Mathew C. "Structure-function studies of agonist binding to the muscle-type nicotinic acetylcholine receptor and the development of a trifunctional non-competitive antagonist suitable for activity-dependent profiling." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/46035.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2008.Vita.
Includes bibliographical references.
The muscle-type nicotinic acetylcholine receptor (AChR) is a ligand-gated ion channel required for fast synaptic transmission at the neuromuscular junction. It is the archetype of the Cys-Loop superfamily of receptors and a prototypic allosteric protein. The muscle-type AChR has two distinct transmitter binding sites found in the extracellular ligand-binding domain. When acetylcholine binds these sites, a series of still unresolved conformational changes occur, leading to opening of the transmembrane pore over 40 A distant from the binding sites. High resolution structures of the intact receptor and the acetylcholine binding protein have provided greater insight into the structural basis of the allosteric mechanism coupling agonist binding and pore opening. However, comprehensive models of the agonist-bound receptor in its closed and open states are still not available. In particular, the details describing the conformation of binding site residues and the dynamics of their interactions with agonists and competitive antagonists are still under investigation. These details are of particular importance to the design of AChR agonists, partial agonists, and competitive antagonists which may have therapeutic potential for treating neuromuscular and neurological pathologies. Using single-channel electrophysiology we investigated details of the agonist-bound open-state transmitter binding sites. Using a series of structurally related organic cations, we observed a structure-activity relationship that suggests cation-n binding interactions are important for open-state affinity. We also conducted a structure-function study to measure kinetic and thermodynamic differences in agonist binding to the two different transmitter binding sites in both the closed and open states. We observed that the two binding sites have unequal affinities for the agonist choline in the closed state and equal affinities in the open state. The state-dependent difference in affinities suggests that binding determinants from the a subunits predominantly determine open-state choline affinity at each site.
(cont.) In the last chapter, we exploit the state-dependent affinities of small molecules for the AChR to develop a probe for live-cell labeling. The ability of a noncompetitive antagonist incorporating state-dependent AChR binding, photoreactivity, and click chemistry moieties was characterized electrophysiologically, and state-dependent photolabeling of AChRs in live cells was demonstrated. A probe with these characteristics is suitable for investigating the activity-dependent changes in AChRs associated with the complex synaptic changes associated with neuromuscular and neurological disorders.
by Mathew C. Tantama.
Ph.D.
49
Teixeira, Odilene de Souza. "TERMINAÇÃO DE BOVINOS AOS 18 MESES COM DIFERENTES CONDIÇÕES SEXUAIS SUPLEMENTADOS EM PASTAGEM DE ARUANA." Universidade Federal de Santa Maria, 2016. http://repositorio.ufsm.br/handle/1/10917.
Full textAbstract:
Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorThis study aimed to evaluate performance, behavior as well as meat and carcass characteristics of beef cattle with different sexual conditions, finished at 18 months, raised on Aruana (Panicum maximum Jacq cv. Aruana) pasture, receiving energy supplementation. The treatments consisted of surgically castrated, immunocastrated or non-castrated animals. The experiment consisted of 39 contemporary male bovine animals with initial body weight of 284.1 ± 31.4 kg and average age of 14 months. Chemical composition analysis and patterns of pasture production did not differ among treatments. Average daily gain, final weight and live weight gain per hectare, were not influenced by the sexual condition. In assessing the agonistic behavior of the animals, non-castrated animals more often displayed aggressive activities such as threats and fights when compared to immunocastrated animals. Feeding behavior, grazing time, rumination and idleness were not affected by treatments. Non-castrated animals spent more time at the feeder (56.20 minutes) than either surgically castrated (41.43 minutes) or immunocastrated, (32.38 minutes).. As for carcass attributes, no difference was found for slaughter weight, hot and cold carcass weight and their respective yields. Regarding Muscle and fat yield per 100 kg of cold casting, non-castrated animals had higher muscle ratio (67.9%) vs. castrated calves (65.1%) or immunocastrated (64,1%) in detriment of the greater proportion of fat found in castrated animals. Regarding meat characteristics, meat from immunocastrated and surgically castrated animals demonstrated color with greater intensity of red and yellow hues. The characteristics evaluated by the taste panel did not differ for any of the evaluated sexual conditions and were classified as "slightly above average". The combination of the correct handling of Aruana grazing and the use of supplementation was promising for finishing cattle with different sexual conditions at 18 months of age, considering that there was no difference in average daily gain, final weight and gain liveweight per hectare. Castrates both surgically as immunocastrated obtained higher yield of fat in the carcass while uncastrated animals have higher muscle performance. In the flesh, there was difference in the color, and steers (surgically or immunocastrated) produced meat prone to lighter red color compared to uncastrated cattle. In choosing the method recommended castration this latter, to be a less invasive method for cattle, which determines greater preservation of animal welfare.
Objetivou-se, mensurar o desempenho, o comportamento e as características de carcaça e carne de bovinos de corte com diferentes condições sexuais, terminados aos 18 meses em pastagem de Aruana, recebendo suplementação energética. Os tratamentos consistiram em novilhos castrados cirurgicamente, imunocastrados ou não castrados. Foram utilizados, para o experimento, 39 bovinos machos, contemporâneos, com peso corporal e idade inicial média de 284,1 ± 31,4 kg e 14 meses, respectivamente. Os resultados referentes à análise da composição bromatológica e os parâmetros produtivos da pastagem não diferiram para os tratamentos. As variáveis, ganho médio diário, peso final e ganho de peso vivo por hectare, não sofreram influência da condição sexual. Ao avaliar o comportamento agonístico dos novilhos verifica-se que os não castrados apresentaram maior número de atividades como ameaças e brigas em relação aos imunocastrados. No comportamento ingestivo, os tempos de pastejo, ócio e ruminação não foram influenciados pelos tratamentos. O tempo de permanência no comedouro dos animais não castrados, 56,20 minutos, foi superior ao detectado para castrados cirurgicamente ou imunocastrados, 41,43 e 32,38 minutos. Nos atributos de carcaça, não foi encontrada diferença para peso de abate, peso de carcaça quente e fria, bem como para seus respectivos rendimentos. No que se refere aos rendimentos de músculo e gordura por 100 kg de carcaça fria, os novilhos não castrados obtiveram maior proporção de músculo (67,9%) ao comparar com novilhos castrados cirurgicamente (65,1%) ou imunocastrados (64,1%), em detrimento da maior proporção de gordura dos animais castrados. Para as características de carne, os novilhos castrados cirurgicamente e imunocastrados dispuseram de carnes com maior intensidade de vermelho e amarelo. As características avaliadas pelo painel de degustadores não diferiram para nenhuma das condições sexuais trabalhadas neste ensaio, sendo classificadas como levemente acima da média . A combinação entre o correto manejo da pastagem de Aruana e o uso de suplementação se mostrou promissora para a terminação de bovinos com diferentes condições sexuais aos 18 meses de idade, considerando-se que não houve diferença para ganho médio diário, peso final e ganho de peso vivo por hectare. Animais castrados tanto cirurgicamente quanto imunocastrados obtiveram maior rendimento de gordura na carcaça, enquanto, animais não castrados apresentam maior rendimento de músculo. Na carne, observou-se diferença para a cor, sendo que novilhos castrados (cirurgicamente ou imunocastrados) produziram carne com tendência a coloração vermelho mais claro, comparado aos bovinos não castrados. Na escolha do método de castração se recomenda essa última, por ser um método menos invasivo para o bovino, o que determina maior preservação do bem- estar animal.
50
Kasten, Chelsea Rae. "Intra-nucleus accumbens shell injections of R(+)- and S(-)- baclofen bidirectionally alter binge-like ethanol, but not saccharin, intake in C57Bl/6J mice." Thesis, Behavioural Brain Research (Elsevier), 2014. http://hdl.handle.net/1805/6453.
Full textAbstract:
Indiana University-Purdue University Indianapolis (IUPUI)It has been proposed that the GABAB receptor subtype plays a role in alcoholism and alcohol use disorders (AUDs) (Cousins et al., 2002; Agabio et al., 2012). Specifically, the GABAB agonist baclofen has been looked at extensively in clinical and pre-clinical studies. In various animal models of chronic and intermittent consumption, baclofen has been shown to both increase (Petry, 1997; Smith et al., 1999; Czachowski et al., 2006; Moore et al., 2007) and decrease (Colombo et al., 2000; 2002; 2005; Stromberg, 2004; Moore et al., 2009) drinking. A critical issue in determining pharmacological effects of a drug is using the appropriate animal model. The drinking-in-the-dark (DID) model, developed by Rhodes et al. (2005, 2007), produces high levels of drinking in a binge-like paradigm and has been used to assess many pharmacological targets (e.g. Kamdar et al., 2007; Gupta et al., 2008; Moore et al., 2007; 2009). While DID produces high-levels of binge drinking, it is unclear what areas of the brain are involved in this behavior. A direct way to target areas that are believed to be involved in the circuitry of particular behaviors is through microinjection of drugs (Kiianmaa et al., 2003). Of particular recent interest involving motivated behaviors and addiction is the nucleus accumbens (Acb) (Everitt & Robbins, 2005); specifically the accumbens shell (AcbSh) (e.g. Rewal et al., 2009, 2012; Nie et al., 2011; Leriche et al., 2008). The current study aimed to investigate the role of GABAB receptors in the AcbSh by examining the ability of two different enantiomers of baclofen to alter ethanol and saccharin intake in male C57BL/6J (B6) mice. B6 mice underwent bilateral cannulation surgery targeting the AcbSh. After 48 hours of recovery time, animals began a five day Drinking-in-the-Dark (DID) procedure where they received 20% ethanol or 0.2% saccharin for two hours, three hours into the dark cycle, each day. Throughout the five drinking sessions, animals were kept in home-cage locomotor activity chambers to monitor activity throughout the drinking cycle. Day 4 drinking was immediately preceded by a mock microinjection, whereas Day 5 drinking was immediately preceded by a drug microinjection. Microinjection of one of five doses of baclofen was given in ng/side dissolved in 200 µl of aCSF (aCSF alone, 0.02 R(+)-, 0.04 R(+)-, 0.08 S(-)-, or 0,16 S(-)-). Intake was recorded every twenty minutes on Days 4 and 5. Retro-orbital sinus blood samples were taken from ethanol animals immediately following the Day 5 drinking period to determine blood ethanol concentrations (BECs). A one-way ANOVA on total Day 4 ethanol consumption revealed no baseline differences between dose groups. A one-way ANOVA on total Day 5 ethanol consumption revealed that the 0.04 R(+)- baclofen dose reduced total drinking, but the 0.16 S(-)- baclofen dose increased total drinking (p’s<0.05). This pattern was reflected in the BECs; 0.04 R(+)- baclofen reduced BECs, whereas 0.16 S(-)- baclofen increased BECs (p’s<0.05). These results were also time-dependent, with R(+)-baclofen reducing drinking in the first 20 minutes of the session and S(-)- increasing drinking in the last 40 minutes of the session. There were no effects on saccharin intake. An issue with the locomotor activity boxes led to unreliable locomotor activity counts. However, because there were no drug effects on saccharin consumption, it was concluded that locomotor effects did not contribute to the decreases or increases in ethanol consumption. These results further implicate the role of GABAB receptors in modulating ethanol intake. The bidirectional effects shown highlight the importance of considering enantioselective drug effects when interpreting data. Finally, these results also support previous conclusions that the AcbSh plays an important role in modulating use of drugs of abuse, but not other reinforcers.