Dissertations / Theses on the topic 'Métabolisme des médicaments'
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 'Métabolisme des médicaments.'
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.
Davi, Horace. "Métabolisme et pharmacocinétique de la minaprine." Montpellier 1, 1986. http://www.theses.fr/1986MON13509.
Full textLe, Louët Hervé. "Caféine et métabolisme des médicaments : influence de la pathologie hépatique." Paris 12, 2003. https://athena.u-pec.fr/primo-explore/search?query=any,exact,990003949340204611&vid=upec.
Full textQuantitative liver function assessment is a major concept in drug biotransformation studies. Caffeine metabolism, which is pluri-enzymatic and under polygenic control, was used to assess the effect of liver disease. Studies concerning primary biliary cirrhosis, alcoholic cirrhosis, hepatitis of viral and drug origin, liver transplantation were conducted. They displayed differential modification of caffeine metabolism pathways according to pathologies. N-acetyltransferase investigation using caffeine test was conducted in chronic autoimmune thrombocytopenic purpura and comparing khmer and caucasian populations. Therapeutic drug monitoring and Pharmacogenomic approach were discussed in comparison
Beyssac, Éric. "Interactions aliments/médicaments : utilisation des composés alimentaires comme vecteur d'administration des médicaments et/ou excipients dans les formes pharmaceutiques." Clermont-Ferrand 1, 1989. http://www.theses.fr/1989CLF15010.
Full textGossein, Catherine. "L'alcool et les médicaments : leurs intéractions." Paris 5, 1993. http://www.theses.fr/1993PA05P171.
Full textDefoy, Daniel. "Étude du métabolisme de médicaments induisant une réaction adverse chez l'homme." Mémoire, Université de Sherbrooke, 2010. http://savoirs.usherbrooke.ca/handle/11143/4069.
Full textLabbé, Gilles. "Inhibition de la B-oxydation mitochondriale des acides gras par divers médicaments." Paris 5, 1988. http://www.theses.fr/1988PA05P619.
Full textCoret, Bernadette. "Métabolisme "in vitro" des médicaments : influence de l'insuffisance rénale et de l'hémodialyse." Paris 5, 1996. http://www.theses.fr/1996PA05P150.
Full textFerrari, Luc. "Interleukine-1 et enzymes du métabolisme des médicaments : mécanismes intracellulaires des effets." Nancy 1, 1993. http://www.theses.fr/1993NAN12438.
Full textSica, Valentina. "Caractérisation de nouveaux médicaments anticancéreux ciblant mitochondrial complexe I." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS207.
Full textIn the context of a project aimed at the development of agents that specifically target hypoxia-inducible factor 1 alpha, BAYER Pharmaceuticals unexpectedly identified novel inhibitors of respiratory complex I, which were able to kill hypoxic cancer cells in vitro and in vivo. Upon modification of a lead compound, several derivatives with favourable pharmacodynamic and pharmacokinetic properties have been identified. These second-generation compounds include BAY87-2243 (B87), which I studied during my PhD thesis work.Throughout the past decade, mitochondria attracted unprecedented attention as targets for the development of novel anticancer regimens with clinical applications. Thus, it seemed important to characterize the potential antineoplastic effects of B87 in detail. My first aim was to test B87 in vitro, in order to identify conditions in which B87 might inhibit the proliferation or reduce the viability of transformed cells. In standard culture conditions (normal nutrient availability and oxygen tension), B87 limited the proliferation of several cancer cell lines (including human non-small cell lung carcinoma H460 cells and human colorectal carcinoma HCT116 cells), but did not promote cell death.Next, I tested the antiproliferative and cytotoxic effects of B87 in combination with currently employed anticancer drugs or natural molecules with putative antineoplastic effects. In this context, I identified a strong synergistic effect between B87 and alpha-ketoglutarate (alphaKG), a central intermediate of the Krebs’ cycle. To characterize the molecular mechanisms underlying such a synergy, I investigated the ability of B87 plus alphaKG to modulate the major bioenergetic cellular circuitries by extracellular flux analysis and mass spectrometry. In both H460 and HCT116 cells, the combinatorial administration of B87 and alphaKG inhibited not only mitochondrial respiration (as expected from B87 alone) but also glycolysis, hence promoting a lethal drop in ATP and glucose-6-phosphate levels.Combining low doses of B87 with alphaKG also exerted robust antineoplastic effects in vivo, in both H460 and HCT116 xenografts growing on immunodeficient mice. In conclusion, alphaKG turned out to boost the anticancer effects of B87 in vitro and in vivo, upon the establishment of a lethal bioenergetic crisis in malignant cells
Belon, Charles. "Le métabolisme phosphocalcique en pédiatrie : étude de quelques variations physiologiques, pathologiques et iatrogènes." Montpellier 1, 1986. http://www.theses.fr/1986MON13506.
Full textLegay, Rémi. "Résonance magnétique nucléaire et médicaments : etude du métabolisme et de la dégradation de médicaments anticancéreux phosphorés, évolution des formulations de 5-fluorouracile." Toulouse 3, 2004. http://www.theses.fr/2004TOU30159.
Full textThis work treats of the study of anticancer drugs with Nuclear Magnetic Resonance (NMR) as major tool of analysis and structural characterization. The aim of a first part is the study of metabolism and degradation of phosphorylated anticancer drugs as cyclophosphamide (CP), ifosfamide (IF), mafosfamide and glufosfamide. For CP and IF, the degradation pathway in aqueous solution of one of their important metabolites (respectively carboxycyclophosphamide and carboxyifosfamide) has been determined and the stability and the behaviour of their alkylating agent (respectively phosphoramide and isophosphoramide mustard) has been studied. In the second part, we studied the evolution of 5-Fluorouracil (5-FU) in the drug vials. Fluorine-19 NMR was used to analyse 5-FU commercial vials then the degradation pathway of 5-FU in the conditions used in the different drug vials has been determined
Pichard, Lydiane. "Modèles "in vitro" humains pour l'étude du métabolisme et des effets secondaires des médicaments." Montpellier 1, 1996. http://www.theses.fr/1996MON1T023.
Full textHenri, Jérôme. "Etude comparative de deux ionophores carboxyliques chez la volaille : apport de la modélisation pharmacocinétique basée sur la physiologie." Poitiers, 2008. http://theses.edel.univ-poitiers.fr/theses/2008/Henri-Jerome/2008-Henri-Jerome-These.pdf.
Full textCarboxylic ionophores used as anticoccidial additives in poultry feed are currently under reevaluation by the European food safety authority in order to assess the safety of the consumer. This work has contributed to the knowledge of pharmacokinetics of monensin in chickens and turkeys and salinomycin in chickens in order to establish some generalities about carboxylic ionophores in poultry. The three examples taken as experimental subject during this thesis have shown a low oral bioavaibility and a rapid elimination driving to a calculated withdrawal period of less than 22 hours in any case. During these works, in vitro and in vivo experiments were used to attribute values to parameters allowing to implement a physiologically based pharmacokinetic model. A physiological model of monensin in chickens has then been tested. Simulations of this model reproduce concentrations observed after a single administration by intravenous or oral route but overestimate concentrations after repeated oral administrations in the supplemented food
Waziers, Isabelle de. "Le Métabolisme intestinal des xénobiotiques et la cancérogénèse colorectale." Paris 5, 1994. http://www.theses.fr/1993PA05P602.
Full textBendriss, Abdenbi. "Méthodologie d'étude in vivo - in vitro du métabolisme hépatique des médicaments chez l'homme : applications à la caractérisation des interactions médicamenteuses au niveau des cytochromes p450 IID6, IA2, de la xanthine oxydase et de la N-acétyltransférase." Besançon, 1990. http://www.theses.fr/1990BESA3707.
Full textLemoine, Antoinette. "Rôle des monooxygénases à cytochrome P-450 et à flavine dans le métabolisme de l'imipramine : étude de la régulation hormonale chez le rat." Paris 11, 1991. http://www.theses.fr/1991PA114837.
Full textMorozova, Svetlana. "Recherche du mécanisme d'action moléculaire de l'agent hypocholestérolémiant et anti-athéromateux, LF 08-0133." Université Louis Pasteur (Strasbourg) (1971-2008), 2003. http://www.theses.fr/2003STR13235.
Full textAtherosclerosis is a disease characterised by lipid accumulation in the vascular wall leading to heart attack or stroke. Hypercholesterolemia is an important risk factor and current treatments are largely based on cholesterol lowering. In spite of proven efficacy of existing drugs, cardiovascular disease still remains the most common cause of death in industrialized countries. LF 08-0133 is an original compound from Fournier Laboratories with hypocholesterolemic and antiatherosclerotic properties. It has further been shown to be an intestinal cholesterol absorption inhibitor (ICAI) in vivo. The aim of this work is to determine the molecular mechanism of action of LF 08-0133. Firstly, the identification of target genes of this compound was attempted in the intestine, liver and aorta of mice. Among the numerous genes of cholesterol metabolism investigated, there was no direct modification of gene expression by LF 08-0133. Additionally, based on the broad gene expression technique employed (RAP-PCR), the compound did not modulate gene expression in the intestine. This does not totally exclude the hypothesis of modification of expression, as the technique employed did not permit a complete coverage of the transcriptome. Secondly, the ICAI mechanism of the drug was investigated by attempting to identify potential intestinal target proteins. LF 08-0133 column immobilisation and subsequent affinity chromatography resulted in the isolation of 11 intestinal protein bands, which are currently being identified. Finally, in an attempt to develop an in vitro model, the ICAI activity of LF 08-0133 was tested in Caco-2 cells (enterocyte) and the drug was found to be inactive. The LF 08-0133 molecular mechanism of action does not appear to involve the regulation of gene expression, but could result from drug – intestinal protein interactions. The Intestine appears to be one of target organs of the compound. Further studies are needed to identify molecular targets of LF 08-0133
Strehle, Axelle. "Characterisation of triterpenoids as TGR5 agonists and their effects on metabolism." Strasbourg, 2009. http://www.theses.fr/2009STRA6149.
Full textMitochondrial dysfunction is implicated in the early stages of diabetes but is not targeted by the available therapies. Mitochondrial functions can be activated by the bile acids-activated GPCR TGR5, in muscle and in adipose tissue. This double effect of TGR5, on mitochondria and GLP-1 secretion, positions this receptor as an interesting target to prevent the early onset of metabolic diseases. To further explore TGR5 potential, our principal challenge was to identify more potent and more selective TGR5 agonists devoid of the pleiotropic effects of bile acids, the only TGR5 agonists known so far. To this end, we used a TGR5 activity assay to screen a plant library. Among the plant extracts tested, Olea Europaea leaves was shown to exhibit an activity supported by the triterpenoid oleanolic acid. In vivo, oleanolic acid showed anti-hyperglycemic activity, improved glucose tolerance and decreased weight gain. Furthermore, oleanolic acid enhanced mitochondria in muscle both in vitro and in vivo. A SAR study based on the triterpenoid scaffold led us to synthetize RG239, a more potent TGR5 agonist in vitro which is inactive in vivo, probably because of poor bioavailability. RG239 is an interesting pharmacological tool to understand TGR5 biology. Indeed, RG239 was shown to induce mitochondria activity and number in muscle and intestinal cell lines in a TGR5 dependant manner. In addition, RG239 stimulated GLP-1 secretion in intestinal enteroendocrine cells in a TGR5 dependant-manner. Altogether, these results confirm TGR5 as therapeutical target and triterpenoids as potential therapeutical agents in the prevention/mitochondria and treatment/GLP-1 of metabolic diseases
Videau, Orianne. "Mise au point d'un cocktail de substrats phénotypant les principales enzymes responsables de la pharmacocinétique des médicaments." Paris 11, 2010. http://www.theses.fr/2010PA114853.
Full textThis PhD thesis was aimed to develop a cocktail of probe substrates allowing the establishment of a human phenotype based on the activity of proteins responsible for drugs pharmacokinetics. My work consisted in the targeted proteins and the probe substrates selection, in the assay method development for the substrates and metabolites, in the validation of this CIME cocktail by means of in vitro and in vivo experiments and finally, in the necessary considerations on the protocol writing of the first clinical study using this cocktail in volunteers
Parks, Alexandre. "Déterminants de la distribution subcellulaire et tissulaire de médicaments cationiques lysosomotropiques et leur effet antiprolifératif." Master's thesis, Université Laval, 2016. http://hdl.handle.net/20.500.11794/27210.
Full textAsk, Kjetil. "Métabolisme pulmonaire et extrapulmonaire du nilutamide." Dijon, 2003. http://www.theses.fr/2003DIJOPE02.
Full textSuleman, Funmilayo Grace. "Localisation et caractérisation biochimique dans le cerveau de rat de deux enzymes de conjugaison des médicaments." Nancy 1, 1995. http://www.theses.fr/1995NAN10460.
Full textRichier, Eric. "Recherche et caractérisation des mécanismes d'action des sels de bis-thiazolium contre Plasmodium falciparum et Babesia divergens." Montpellier 2, 2004. http://www.theses.fr/2004MON20046.
Full textDulcire, Brigitte. "Contribution à l'étude du métabolisme de la diosmine chez l'homme : synthèse de la B-U-13C diosmine." Montpellier 2, 1988. http://www.theses.fr/1988MON20166.
Full textBachir-Cherif, Dalila. "Influence of bile-duct cannulation on the expression of DMPK-relevant enzymes in the rat." Strasbourg, 2011. https://publication-theses.unistra.fr/restreint/theses_doctorat/2011/BACHIR-CHERIF_Dalila_2011.pdf.
Full textEssassi, Dalila. "Liaisons sanguines, transferts cérébral et hépatique de la pipequaline." Paris 12, 1991. http://www.theses.fr/1991PA120008.
Full textPicard, Nicolas. "Etudes in vitro et in vivo du métabolisme du mycophénolate et des interactions métaboliques entre médicaments immunosuppresseurs." Limoges, 2005. http://aurore.unilim.fr/theses/nxfile/default/5e16d2f3-56fd-45eb-8f46-df30fc9267e3/blobholder:0/2005LIMO310G.pdf.
Full textThe immunosuppressive drugs have a narrow therapeutic window and thus require Therapeutic Drug Monitoring (TDM). Metabolism could lead to changes in drug exposure as well as to drug-drug interactions. It should be considered for the choice of drug combination and dosages. This work focuses on the metabolism of mycophenolic acid (MPA, the active moiety of mycophenolate mofetil, Cellcept®) and drug-drug interactions between immunosuppressive drugs. MPA phase I and phase II metabolic pathways were characterized in vitro (metabolites, enzyme isoforms, tissue locations). These studies showed that UGT 1A9 and UGT 2B7 are the main contributors to the production of the two main MPA metabolites (MPA-phenyl-glucuronide, MPAG and MPA-acyl-glucuronide, AcMPAG). UGT 1A9 genetic polymorphism was not associated with changes in MPAG plasma concentrations. On the contrary, the UGT 2B7 G-840A mutation influenced AcMPAG exposure, a metabolite presumably responsible for a part of MMF toxicity. In renal transplant patients, we observed variations in the exposure to MPA and metabolite, depending on the immunosuppressive drug associated (cyclosporin, tacrolimus, or sirolimus). This seems to involve two different interactions: an effect of cyclosporin on MPAG biliary excretion as well as an effect of tacrolimus on MPA pharmacokinetics (of which the mechanism remains to be explored). Finally, based on in vitro experiments, we suggestthat the metabolic interaction between cyclosporin and sirolimus mainly involves CYP 3A4. CYP 3A5, which largely contributes to sirolimus bioavailability (when expressed), would only play a minor role in this interaction
Benali, Saïda. "Etude analytique de la mise sous forme de nanocapsules de deux substances lipophiles : conséquences sur le métabolisme de la phénylbutazone." Rouen, 2000. http://www.theses.fr/2000ROUES043.
Full textRoy, Geneviève. "Étude comparant les effets secondaires métaboliques des antipsychotiques de seconde génération chez les enfants et les adolescents à ceux chez les adultes." Thesis, Université Laval, 2010. http://www.theses.ulaval.ca/2010/27396/27396.pdf.
Full textLasocki, Sigismond. "Métabolisme du fer dans l'anémie de réanimation." Paris 7, 2009. http://www.theses.fr/2009PA077088.
Full textAnemia is frequent among critically ill patients. It results from both inflammation and blood losses. It is usually considered that these critically ill patients have an inflammatory iron profile, with iron being stored in tissue macrophages. However, these two mechanisms exert opposite effects on iron metabolism regulation by the master regulator: hepcidin. During this work, we have developed and characterized a mice model of critical care anemia, associating an inflammatory peritonitis and repeated phlebotomies. We observed that erythropoiesis stimulation dominates over inflammation, with decreased hepcidin expression. This allowed the mobilization of spleen iron, despite the inflammation. In a preliminary study, we observed that intravenous iron toxicity was not enhanced in mice with peritonitis compared to control animals. Furthermore, we confirmed. In a prospective observational study in critically ill patients, that hepcidin may be repressed, even in the presence of inflammation. Taken together, these data suggest that iron may be proposed to treat some anemic critically ill patients
Gemin, Olivier. "Activité spécifique des cytochromes P450 humains : moyens d'études et stratégies d'utilisation." Paris 5, 1996. http://www.theses.fr/1996PA05P175.
Full textYebga, Albert. "Etude de l'influence de l'introduction du soufre sur le métabolisme de barbituriques porteurs d'une chaîne ramifiée." Rouen, 1994. http://www.theses.fr/1994ROUE04NR.
Full textDasse, Marie-Hélène. "Influence de l'alimentation et de l'heure sur la prise du médicament : optimisations envisageables des traitements." Bordeaux 2, 1992. http://www.theses.fr/1992BOR2P022.
Full textGuerber, Isabelle. "Validation d'une méthode "in vitro" d'étude du métabolisme sur microsomes hépatiques." Paris 5, 1992. http://www.theses.fr/1992PA05P066.
Full textMartin, Bernabe Alfonso. "Une approche protéomique pour comprendre les adaptations métaboliques du cancer du poumon non à petites cellules." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAS027.
Full textLung cancers are broadly classified into two main groups: small cell lung cancer and non-small cell lung cancer (NSCLC), which accounts for approximately 83% of all lung cancer cases with an overall 5-year survival rate of 21%. Conventional therapies in NSCLC including radiotherapy and platinum-based chemotherapy lack specificity and often cause severe side effects as they affect healthy cells. To address this problem, targeted therapies have been successfully used due to their specificity for cancer cells. Targeted therapies against epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements have been shown to be effective in NSCLC. However, therapeutic response may be limited due to drug resistance. This is the case of patients whose tumors harbor activating KRAS mutation that leads to constitutive activity of RAS signaling independent of upstream signals. For this reason, a better comprehension of tumor progression and resistance is needed to improve cancer treatments. To date, approaches targeting oncogenic KRAS have been unsuccessful. Given the importance of metabolic reprogramming in multiple cancers including lung cancer and the regulatory role of KRAS signaling. We explored the metabolic reprogramming of KRAS-driven NSCLC cells to find vulnerabilities in the altered metabolism that can be exploited as therapeutic targets.For this, we characterized the proteome of NSCLC cell lines (A549 and NCI-H460) harboring activating mutations of the oncogene KRAS with particular focus on metabolic enzymes. We found not only up-regulation expression of glycolytic enzymes, which is frequently found in cancer as part of the “Warburg effect”, but also a remarkable up-regulation of the pentose phosphate pathway (PPP) in both oxidative and non-oxidative branches. Based on this study, we evaluated the feasibility of use PPP enzyme (glucose 6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD) and transketolase (TKT)) as targets for improve or develop of new therapies.Recently, protein lysine acetylation (KDAC) has emerged as a metabolism-coordinating mechanism and mounting evidence has shown that acetylation regulation of metabolic enzymes plays a major role in cancer. Consequently, lysine deacetylases inhibitors (KDACIs) have drawn attention not only as promising strategies for therapeutic intervention but also as tool for studying the role of lysine acetylation in NSCLC metabolic reprogramming. Furthermore, metabolic reprogramming also depends strongly on the tumor microenvironment such as oxygen level. Therefore, we also analyzed the inhibition of KDAC under normoxic and hypoxic conditions in order to better understand the adaptive strategies under such perturbations. Our results showed that KDACIs induce low cell proliferation, differentiation, cell cycle arrest and apoptosis accompanied by a change in the tumor metabolic phenotype enhanced under hypoxia. Together, these results allow us to better understand how KDACIs control metabolic pathways under hypoxia in NSCLC
Eyzat, Virginie. "Etude du métabolisme intermédiaire des médicaments dans des microsomes de foie de rat : application au cas particulier de l'alpidem." Paris 5, 1991. http://www.theses.fr/1991PA05P176.
Full textLiu, Huifang. "Développements chromatographiques pour l'étude du polymorphisme de la glucuronoconjugaison des médicaments chez l'homme." Nancy 1, 1990. http://www.theses.fr/1990NAN10552.
Full textNouette-Gaulain, Karine. "Effets de l'hypoxie chronique sur le métabolisme énergétique cardiaque : potentialisation de la cardiotoxicité des anesthésiques locaux." Bordeaux 2, 2003. http://www.theses.fr/2003BOR21061.
Full textChronic hypoxia induces an adaptation in energy metabolism with a decrease in ATP demand. Time course of differential mitochondrial energy metabolism adaptation to 14 days and 21 days of hypobaric hypoxia (0. 5 atm) has been investigated in right and left ventricles. A decrease in oxidative capacities in right ventricle occured after 21 days of chronic hypoxia, whereas they were altered in left ventricle since 14 days of chronic hypoxia. Normoxia recovery did not totally reverse these metabolic changes. Local anesthetics impaired oxidative phosphorylation and decreased ATP synthesis. This effect could in part explain bupivacaine-induced cardiac toxicity. The mitochondrial effects of these molecules were not stereospecific but appeared mainly to depend upon the lipid solubility of the molecules. Chronic hypoxia increased the mitochondrial toxicity of local anesthetics in the heart
Fellous, Robert. "Pharmacocinétique métabolisme et toxicité de 2 agents intercalants : le ditercalinium et le SR - 95156 B." Paris 5, 1989. http://www.theses.fr/1989PA05P604.
Full textTomkiewicz, Céline. "Régulation de l'expression des gènes des transaminases par les médicaments et les médiateurs de l' inflammation." Paris 5, 2001. http://www.theses.fr/2001PA05P630.
Full textLegendre, Claire. "Adaptation cellulaire et moléculaire des cellules d'hépatome humain HepaRG à un environnement hypoxique." Rennes 1, 2009. http://www.theses.fr/2009REN1S055.
Full textReduced oxygen level, or hypoxia, is frequently encountered in solid tumours and contributes to drug resistance. Hypoxia is also associated with invasive phenotype and correlated to poor prognosis and mortality. The role of hypoxia in hepatocellular carcinoma biology is not fully understood. Therefore, there is a need for developing in vitro models mimicking hypoxic conditions find within solid tumours using hepatic tumour cells. Highly differentiated human hepatoma HepaRG cells respond to hypoxia by a switch from aerobic to anaerobic glycolysis. Moreover, we showed that hypoxia also repressed drug-metabolizing enzymes expression. These repressions could therefore strongly compromise chemotherapy effectiveness on tumour cells within hypoxic environment. Furthermore, HepaRG cells cultured under hypoxic versus normoxic conditions might represent a new strategy to test different types of therapeutic molecules in order to predict their effectiveness
Blankert, Bertrand. "Développement de méthodes électroanalytiques hybrides pour l'étude de la biotransformation des médicaments." Doctoral thesis, Universite Libre de Bruxelles, 2006. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210863.
Full textNotre champ d'investigation s'est plus spécifiquement focalisé sur deux familles de molécules psychotropes (les phénothiazines, et une dibenzoazépine). Celles-ci connaissent un usage thérapeutique intensif et un regain d’intérêt pour des applications nouvelles, mais leur utilisation optimale souffre de l’existence d'effets secondaires physiopathologiques importants et dont l’étiologie est encore mal connue.
En premier lieu, les résultats de la voltampérométrie cyclique et les différentes modulations en ligne d'une cellule électrochimique couplée à la détection par spectrométrie de masse, nous ont permis de mettre en évidence des différences essentielles dans le devenir des phénothiazines quant aux produits d'oxydations générés. Plus précisément, un comportement clairement distinct entre les phénothiazines garnies de deux (2C) ou trois carbones (3C) entre les deux azotes au niveau de leur chaîne latérale a pu être mis en évidence. Les phénothiazines 3C s'oxydent de manière classique en leur sulfoxyde correspondant. Par contre, les phenothiazines 2C, conjointement à la formation de leur sulfoxyde, souffrent dans des conditions énergiques d’oxydation (persulfate, potentiel élevé) d'une rupture de la chaîne latérale et libèrent la phénothiazine base aisément oxydable et donc subissant elle-même une oxydation. Au vu des structures moléculaires en trois dimensions, nous émettons l’hypothèse que volume trop important de la chaîne latérale des phénothiazines 2C empêcherait le déploiement aisé des structures aromatiques en un radical cation coplanaire lors du phénomène d'oxydation. Les tensions intrastructurelles apparues conduiraient au bris de la chaîne latérale. Différents modes d'oxydation (chimique, électrochimique, enzymatique) ont été utilisés et laissent chacun apparaître la dépendance directe entre la puissance de l'agent oxydant appliqué et les produits d'oxydation obtenus. Chaque technique de détection, de manière individuelle, a bien confirmé la dualité entre les deux groupes de molécules. La mise en commun des divers résultats nous a permis l'identification irrévocable des espèces intermédiaires instables et des composés finaux. Par corollaire, nous avons pu postuler un schéma général d'oxydation pour les dérivés phénothiaziniques. Il nous paraît intéressant de transposer nos résultats aux biotransformations des phénothiazines car les produits identifiés ne possèdent pas l'activité pharmacologique du composé parent mais présentent un profil toxicologique bien répertorié dans la littérature. Nos résultats suggèrent d’approfondir les études de biotransformation afin de déterminer si ‘l’éclatement’ oxydatif des phénothiazines 2C est également observé in vivo. Une relation cause/effet de ces métabolites pourrait ainsi être établie.
En deuxième point, au travers de l'association CE/SM ou CE/CL/SM, nous avons étudié l’électroxydation de la clozapine. La génération et l'identification des principaux métabolites de phases I et II, illustre un mimétisme certain avec le CYP450, et nous a permis de confirmer de nombreuses données de la littérature quant à l'oxydation in vivo et in vitro de la clozapine. L'oxydation électrochimique ne génère cependant pas l'ensemble des réactions de métabolisation prises en charge par le système CYP450. Lors de la combinaison CE/SM, par l'absence de séparation chromatographique dans cette configuration, le spectre de masse présente un pic correspondant à un intermédiaire à demi-vie courte, difficilement et rarement mis en évidence: l'ion nitrénium. Cette espèce hautement réactive envers les fonctions thiols des petites molécules et des protéines, se trouve très régulièrement tenue pour responsable majeur de la toxicité avérée de la clozapine.
L'apparition plus abondante de dérivés déméthylés démontre l'influence du potentiel appliqué à l'électrode de travail lors de l'oxydation électrochimique. En effet, les processus de déméthylation nécessitent des potentiels élevés pour être observés. En présence de glutathion, aux différents pics antérieurement identifiés, des pics supplémentaires relatifs à la formation d'adduits de GSH sur la CLZ apparaissent. Les courbes voltampérométriques réalisées sur la clozapine suggèrent la distinctement la formation de l'ion nitrénium et d'une nouvelle espèce aisément électroréduite, probablement une structure quinone imine. L'addition de GSH provoque la disparition des pics de réduction de la CLZ. Ces comportements en VC corroborent les interprétations issues des mesures par couplage EC/CL/SM.
La dernière partie de notre travail a consisté en la construction d'un biocapteur à pâte de carbone solide avec inclusion au sein de cette matrice de peroxydase de raifort. Basé sur la capacité reconnue de l'HRP à reproduire in vitro des produits d'oxydation similaires à la métabolisation in vivo, nous avons exploité un tel biocapteur pour l'analyse de la clozapine et de composés thiols. Une compréhension fine du mécanisme opérationnel intrinsèque du biocapteur a pu être suggérée. La génération à la surface de l'électrode de l'ion nitrénium par oxydation enzymatique de la clozapine par l'HRP, suivie de sa réduction immédiate fournit un courant ampérométrique substantiel. Sous des conditions de pH optimales, ce courant de réduction autorise la détermination quantitative de la clozapine dans un domaine de linéarité compris entre 1 x 10-5 M et 1 x 10-6 M. L'addition de composés thiols dans le milieu occasionne une chute de courant par action de ceux-ci sur la structure radical cation ou nitrénium par addition nucléophile. La disparition de l'ion nitrénium et la formation d'un adduit GSH-CLZ inhibent tout processus de réduction à l'électrode du biocapteur. Cette diminution de courant proportionnelle aux concentrations en thiols introduits, permet la détermination quantitative de dérivés thiols. Les courbes de calibration exprimées en pourcentage d'inhibition conduisent facilement à l'évaluation de la constante d'inhibition (Ki) et de CI50. L'étude de la réponse ampérométrique de la clozapine à l'EPC/HRP en l'absence ou présence d'un dérivé thiol envisagé permet la détermination de Km et de caractériser le type d'inhibition qui entre en jeu. De tels paramètres cinétiques nous ont habilités à classer les thiols considérés en fonction de leur puissance réactionnelle envers les substances oxydées de la clozapine.
Au terme de ce travail, nous espérons avoir illustré, par l’étude de quelques molécules modèles, l’intérêt de la mise en œuvre des techniques électrochimiques couplées à l’élément biologique ou à la spectrométrie de masse. Des améliorations au niveau de la cellule électrochimique sont envisageables par l’emploi d’électrodes modifiées, elles laissent entrevoir la possibilité de mimer totalement le système CYP450.
Les résultats fournis par ces techniques hybrides et par voltampérométrie cyclique sont complémentaires, ils procurent un éventail d'informations d'une utilité estimable pour une application dans des études prédictives précoces de candidats médicament.
Doctorat en Sciences biomédicales et pharmaceutiques
info:eu-repo/semantics/nonPublished
Bayad, Jamal. "Immortalisation de lignées cellulaires hépatocytaires : expression et régulation des enzymes du métabolisme des xenobiotiques." Nancy 1, 1991. http://www.theses.fr/1991NAN10450.
Full textFabre, Nicolas. "Méthodes d'étude in vitro et in vivo des interactions métaboliques : exemples d'application à un criblage de molécules." Paris 5, 1999. http://www.theses.fr/1999PA05P031.
Full textRigolot, Xavier. "Exploration des paramètres biochimiques et de la respiration mitochondriale dans le modèle de foie isolé et perfusé de rat." Paris 5, 1994. http://www.theses.fr/1994PA05P219.
Full textTheodorou, Vassilia. "Relations entre motricité, transit et absorption hydrique au niveau du colon : approche physiologique et pharmacologique." Toulouse, INPT, 1992. http://www.theses.fr/1992INPT034A.
Full textLafuente-Lafuente, Carmelo. "Evaluation des médicaments antiarythmiques dans le traitement au long cours de la fibrillation auriculaire : efficacité clinique et rapport bénéfice / risque, accumulation de l'Amiodarone dans le tissu gras et analyse de décision chez les sujets agés." Paris 5, 2009. http://www.theses.fr/2009PA05P627.
Full textAtrial fibrillation (AF) is frequent and increase morbi-mortality. Several antiarrhythmic drugs (AAR) are employed for treating AF. OBJECTIVES: a) better define the risk-benefit ratio of each AAR; b) study the key determinants of therapeutic decision, particularly in elderly patients. RESEARCHS CONDUCTED: 1- AAR for maintaining sinus rhythm after cardioversion of AF: A systematic review 45 good-quality randomized controlled trials (12 559) were pooled in a meta-analysis. Several classes I and III AAR are effective to reduce AF recurrence rate but all increase adverse events, none reduces mortality and those of IA increased it (OR 2. 39). 2- Amiodarone concentrations in plasma and fat tissue and related toxicity. We measured trough concentrations of amiodarone in plasma and fat tissue in 30 patients on chronic treatment. No excessive accumulation of amiodarone in tissue responsible of its toxicity was found. Adverse effects were correlated with treatment duration, but not with plasma or adipose tissue concentrations. 3- Choice of long term treatment of AF in elderly patients: a decision analysis. We developed a Markov decision analytic model to compare 4 therapeutic strategies in two hypothetical cohorts of patients, 60 and 80 years old. Despite variations in events rates, differences between strategies in terms QALYs were small. All results remained the same in elder patients. CONCLUSIONS: Several AAR are effective to prevent AF recurrence, but there is no proof of a clear clinical benefit. Choice of a long-term pharmacological treatment should be individualized. The key determinants are equal in younger and older patients
Mette-Litique, Carole. "Structural and functional analysis of SHP : A powerful regulator of nuclear hormone receptors." Université Louis Pasteur (Strasbourg) (1971-2008), 2006. https://publication-theses.unistra.fr/restreint/theses_doctorat/2006/METTE-LITIQUE_Carole_2006.pdf.
Full textSHP (Small Heterodimer Partner (NR0B2)), a particular member of the mammalian nuclear hormone receptor family which lacks the DNA binding domain, directly modulates the activities of a number of bona fide nuclear receptors by acting as an inducible transcriptional co-repressor. Past efforts at dissecting underlying molecular mechanisms, and at identifying the target factors and target genes, uncovered the regulatory involvement of SHP in diverse metabolic functions such as the catabolism of cholesterol and prompted further clarification on this emerging pathway for drug target discovery. In the first part of this thesis, we report on an extensive series of prokaryotic as well as eukaryotic SHP over expression experiments. In most of the expression systems explored, SHP stayed well expressed but insoluble, compacted to 90% in inclusion bodies. As a consequence the structural analysis of SHP could not be performed. In order to further analyze the function of this non conventional nuclear hormone receptor, we performed in the second section of the thesis a molecular analysis of the interaction between SHP and other nuclear hormone receptors by transrepresion assay. Morevover we report on a Yeast-Two- Hybrid Screen performed with SHP as a bait and the identification and following characterization of a new partner of SHP, the RAR-related Orphan receptor (ROR). To further understand the role of SHP in vivo, we characterized by DNA microarrays the expression profiles genome wide from SHP null mice and wild type livers. These analyses enabled us to decipher known and novel SHP target genes involved in the lipid homeostasis, the apoptosis and the embryonic development. The study opens new perspectives to establish the SHP pathway as potential therapeutic target for the metabolic syndrome
Ivanova, Maria. "New access to difluoromethylphosphonate-containing molecules : via a copper-mediated approach." Thesis, Normandie, 2017. http://www.theses.fr/2017NORMIR14.
Full textSince several decades, the organofluorine chemistry is a research area of strong interest. While plenty of original and elegant methodologies were developed to introduce various fluorinated groups, the CF2PO(OEt)2 residue was scarcely spotlighted. This contrasts with its unique and highly valuable properties. Indeed, the CF2PO(OEt)2 moiety proved to be a metabolically stable bioisoster of the in vivo unstable phosphate group. As a result, approaches to incorporate this motif onto molecules were developed albeit still restricted to few transformations. In this PhD thesis, we would like to propose a general and straightforward method to access CF2PO(OEt)2-containing molecules. A first part was dedicated to the introduction of the CF2PO(OEt)2 motif on aryl, heteroaryl, vinyl and alkynyl iodonium salts, by generating the CuCF2PO(OEt)2 species (Chapter II). Then, the utility and the generality of this transformation were further demonstrated using R-X (R = vinyl, allyl and benzyl) as well as disulfides as the electrophiles. Besides, a Ullmann-type cross-coupling reaction proceeding at room temperature was also studied. Finally, the divergent reactivity of the CuCF2PO(OEt)2 species toward α-diazoesters, by a simple change of copper salt, was investigated (Chapter III). This approach was then extended to α-bromoketone derivatives to access the a-SCF2PO(OEt)2 ketones (Chapter IV)
Silvie, Muriel. "Eléments de pharmacocinétique de l'itraconazole : suivi thérapeutique chez l'enfant et métabolisme "in vitro" sur microsomes hépatiques humains." Paris 5, 1994. http://www.theses.fr/1994PA05P176.
Full text