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Статті в журналах з теми "3, 3', 5-triiodo-l-thyronine(t3)":
1
Chatonnet, Fabrice, Frédéric Picou, Teddy Fauquier, and Frédéric Flamant. "Thyroid Hormone Action in Cerebellum and Cerebral Cortex Development." Journal of Thyroid Research 2011 (2011): 1–8. http://dx.doi.org/10.4061/2011/145762.
Анотація:
Thyroid hormones (TH, including the prohormone thyroxine (T4) and its active deiodinated derivative 3,,5-triiodo-L-thyronine (T3)) are important regulators of vertebrates neurodevelopment. Specific transporters and deiodinases are required to ensure T3 access to the developing brain. T3 activates a number of differentiation processes in neuronal and glial cell types by binding to nuclear receptors, acting directly on transcription. Only few T3 target genes are currently known. Deeper investigations are urgently needed, considering that some chemicals present in food are believed to interfere with T3 signaling with putative neurotoxic consequences.
2
Markova, Natalyia, Anton Chernopiatko, Careen A. Schroeter, Dmitry Malin, Aslan Kubatiev, Sergey Bachurin, João Costa-Nunes, Harry M. W. Steinbusch, and Tatyana Strekalova. "Hippocampal Gene Expression of Deiodinases 2 and 3 and Effects of 3,5-Diiodo-L-Thyronine T2 in Mouse Depression Paradigms." BioMed Research International 2013 (2013): 1–14. http://dx.doi.org/10.1155/2013/565218.
Анотація:
Central thyroid hormone signaling is important in brain function/dysfunction, including affective disorders and depression. In contrast to 3,3′,5-triiodo-L-thyronine (T3), the role of 3,5-diiodo-L-thyronine (T2), which until recently was considered an inactive metabolite of T3, has not been studied in these pathologies. However, both T3 and T2 stimulate mitochondrial respiration, a factor counteracting the pathogenesis of depressive disorder, but the cellular origins in the CNS, mechanisms, and kinetics of the cellular action for these two hormones are distinct and independent of each other. Here, Illumina and RT PCR assays showed that hippocampal gene expression of deiodinases 2 and 3, enzymes involved in thyroid hormone regulation, is increased in resilience to stress-induced depressive syndrome and after antidepressant treatment in mice that might suggest elevated T2 and T3 turnover in these phenotypes. In a separate experiment, bolus administration of T2 at the doses 750 and 1500 mcg/kg but not 250 mcg/kg in naive mice reduced immobility in a two-day tail suspension test in various settings without changing locomotion or anxiety. This demonstrates an antidepressant-like effect of T2 that could be exploited clinically. In a wider context, the current study suggests important central functions of T2, whose biological role only lately is becoming to be elucidated.
3
Petersen, K. F., G. W. Cline, J. B. Blair, and G. I. Shulman. "Substrate cycling between pyruvate and oxaloacetate in awake normal and 3,3'-5-triiodo-L-thyronine-treated rats." American Journal of Physiology-Endocrinology and Metabolism 267, no. 2 (August 1, 1994): E273—E277. http://dx.doi.org/10.1152/ajpendo.1994.267.2.e273.
Анотація:
Substrate cycling between pyruvate and oxaloacetate was assessed in awake 24-h fasted normal and triiodothyronine (T3)-treated rats. After a 20- or 60-min infusion of [3-13C]alanine (99% enriched, 12 mg/min) the 13C enrichments of liver glucose and alanine carbons were analyzed by 13C and 1H nuclear magnetic resonance spectroscopy and gas chromatography-mass spectrometry. Substrate cycling from phosphoenolpyruvate to pyruvate [via pyruvate kinase (PK)] and from oxaloacetate to pyruvate [via malic enzyme (ME)] relative to the pyruvate carboxylase (PC) flux [i.e., (PK+ME)/PC] was assessed by the ratio of the 13C enrichment of C-2 alanine relative to that in C-5 glucose. In the normal rats (PK+ME)/PC was 0.26 +/- 0.07 (n = 7, t = 20 min) and 0.37 +/- 0.08 (n = 4, t = 60 min). In the T3-treated rats the (PK+ME)/PC increased four- to fivefold to 1.03 +/- 0.19 (n = 8, t = 20 min) and to 1.83 +/- 0.19 (n = 3, t = 60 min) (P < 0.05 vs. normal rats). The liver enzyme activity of PK did not change with T3 treatment (normal 14.22 +/- 5.25 U/g liver vs. T3 treated 13.40 +/- 1.10 U/g liver), whereas both the enzyme activity ratio of PK (normal 0.47 +/- 0.15 vs. T3 treated 0.77 +/- 0.03, P < 0.05) and the activity of ME (normal 0.89 +/- 0.30 U/g liver vs. T3 treated 4.25 +/- 0.60 U/g liver, P < 0.05) increased with T3 treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
4
Silvestri, Elena, Assunta Lombardi, Maria Coppola, Alessandra Gentile, Federica Cioffi, Rosalba Senese, Fernando Goglia, Antonia Lanni, Maria Moreno, and Pieter de Lange. "Differential Effects of 3,5-Diiodo-L-Thyronine and 3,5,3’-Triiodo-L-Thyronine On Mitochondrial Respiratory Pathways in Liver from Hypothyroid Rats." Cellular Physiology and Biochemistry 47, no. 6 (2018): 2471–83. http://dx.doi.org/10.1159/000491620.
Анотація:
Background/Aims: Both 3,5-diiodo-L-thyronine (3,5-T2) and 3,5,3’-triiodo-L-tyronine (T3) affect energy metabolism having mitochondria as a major target. However, the underlying mechanisms are poorly understood. Here, using a model of chemically induced hypothyroidism in male Wistar rats, we investigated the effect of administration of either 3,5-T2 or T3 on liver oxidative capacity through their influence on mitochondrial processes including: proton-leak across the mitochondrial inner membrane; complex I-, complex II- and glycerol-3-phosphate-linked respiratory pathways; respiratory complex abundance and activities as well as individual complex aggregation into supercomplexes. Methods: Hypothyroidism was induced by propylthiouracil and iopanoic acid; 3,5-T2 and T3 were intraperitoneally administered at 25 and 15 µg/100 g BW for 1 week, respectively. Resulting alterations in mitochondrial function were studied by combining respirometry, Blue Native-PAGE followed by in-gel activity, and Western blot analyses. Results: Administration of 3,5-T2 and T3 to hypothyroid (hypo) rats enhanced mitochondrial respiration rate with only T3 effectively stimulating proton-leak (450% vs. Hypo). T3 significantly enhanced complex I (+145% vs. Hypo), complex II (+66% vs. Hypo), and glycerol-3 phosphate dehydrogenase (G3PDH)-linked oxygen consumptions (about 6- fold those obtained in Hypo), while 3,5-T2 administration selectively restored Euthyroid values of complex II- and increased G3PDH- linked respiratory pathways (+165% vs. Hypo). The mitochondrial abundance of all respiratory complexes and of G3PDH was increased by T3 administration whereas 3,5-T2 only increased complex V and G3PDH abundance. 3,5-T2 enhanced complex I and complex II in gel activities with less intensity than did T3, and T3 also enhanced the activity of all other respiratory complexes tested. In addition, only T3 enhanced individual respiratory component complex assembly into supercomplexes. Conclusions: The reported data highlight novel molecular mechanisms underlying the effect elicited by iodothyronine administration to hypothyroid rats on mitochondrial processes related to alteration in oxidative capacity in the liver. The differential effects elicited by the two iodothyronines indicate that 3,5-T2, by influencing the kinetic properties of specific mitochondrial respiratory pathways, would promote a rapid response of the organelle, while T3, by enhancing the abundance of respiratory chain component and favoring the organization of respiratory chain complex in supercomplexes, would induce a slower and prolonged response of the organelle.
5
Lin, Hung-Yun, Mingzeng Sun, Heng-Yuan Tang, Cassie Lin, Mary K. Luidens, Shaker A. Mousa, Sandra Incerpi, George L. Drusano, Faith B. Davis, and Paul J. Davis. "l-Thyroxine vs. 3,5,3′-triiodo-l-thyronine and cell proliferation: activation of mitogen-activated protein kinase and phosphatidylinositol 3-kinase." American Journal of Physiology-Cell Physiology 296, no. 5 (May 2009): C980—C991. http://dx.doi.org/10.1152/ajpcell.00305.2008.
Анотація:
3,5,3′-Triiodo-l-thyronine (T3), but not l-thyroxine (T4), activated Src kinase and, downstream, phosphatidylinositol 3-kinase (PI3-kinase) by means of an αvβ3 integrin receptor on human glioblastoma U-87 MG cells. Although both T3 and T4 stimulated extracellular signal-regulated kinase (ERK) 1/2, activated ERK1/2 did not contribute to T3-induced Src kinase or PI3-kinase activation, and an inhibitor of PI3-kinase, LY-294002, did not block activation of ERK1/2 by physiological concentrations of T3 and T4. Thus the PI3-kinase, Src kinase, and ERK1/2 signaling cascades are parallel pathways in T3-treated U-87 MG cells. T3 and T4 both caused proliferation of U-87 MG cells; these effects were blocked by the ERK1/2 inhibitor PD-98059 but not by LY-294002. Small-interfering RNA knockdown of PI3-kinase confirmed that PI3-kinase was not involved in the proliferative action of T3 on U-87 MG cells. PI3-kinase-dependent actions of T3 in these cells included shuttling of nuclear thyroid hormone receptor-α (TRα) from cytoplasm to nucleus and accumulation of hypoxia-inducible factor ( HIF)- 1α mRNA; LY-294002 inhibited these actions. Results of studies involving αvβ3 receptor antagonists tetraiodothyroacetic acid (tetrac) and Arg-Gly-Asp (RGD) peptide, together with mathematical modeling of the kinetics of displacement of radiolabeled T3 from the integrin by unlabeled T3 and by unlabeled T4, are consistent with the presence of two iodothyronine receptor domains on the integrin. A model proposes that one site binds T3 exclusively, activates PI3-kinase via Src kinase, and stimulates TRα trafficking and HIF- 1α gene expression. Tetrac and RGD peptide both inhibit T3 action at this site. The second site binds T4 and T3, and, via this receptor, the iodothyronines stimulate ERK1/2-dependent tumor cell proliferation. T3 action here is inhibited by tetrac alone, but the effect of T4 is blocked by both tetrac and the RGD peptide.
6
Scapin, Sergio, Silvia Leoni, Silvana Spagnuolo, Anna Maria Fiore, and Sandra Incerpi. "Short-term effects of thyroid hormones on Na+-K+-ATPase activity of chick embryo hepatocytes during development: focus on signal transduction." American Journal of Physiology-Cell Physiology 296, no. 1 (January 2009): C4—C12. http://dx.doi.org/10.1152/ajpcell.90604.2007.
Анотація:
Nongenomic effects of thyroid hormones on Na+-K+-ATPase activity were studied in chick embryo hepatocytes at two different developmental stages, 14 and 19 days of embryonal age, and the signal transduction pathways involved were characterized. Our data showed the following. 1) 3,5,3′-Triiodo-l-thyronine (T3) and 3,5-diiodo-l-thyronine (3,5-T2) rapidly induced a transient inhibitory effect on the Na+-K+-ATPase; the extent and duration depended on the developmental age of the cells. 2) 3,5-T2 behaved as a true hormone and fully mimicked the effect of T3. 3) Thyroxine had no effect at any of the developmental stages. 4) The inhibition of Na+-K+-ATPase was mediated by activation of protein kinase A, protein kinase C, and phosphoinositide 3-kinase, suggesting several modes of modulation of ATPase activity through phosphorylation at different sites. 5) The MAPK pathway did not seem to be involved in the early phase of hormone treatment. 6) The nonpermeant analog T3-agarose inhibited Na+-K+-ATPase activity in the same way as T3, confirming that hormone signaling initiated at a receptor on the plasma membrane. From these results, it can be concluded that the cell response mechanisms change rapidly and drastically within the early phase of embryo growth. The differences found at the two stages probably reflect the different roles of thyroid hormones during development and differentiation.
7
HALPERIN, YITZCHAK, LAWRENCE E. SHAPIRO, and MARTIN I. SURKS. "Medium 3,5,3′-Triiodo-L-thyronine (T3) and T3Generated from L-Thyroxine Are Exchangeable in Cultured GC cells*." Endocrinology 127, no. 3 (September 1990): 1050–56. http://dx.doi.org/10.1210/endo-127-3-1050.
8
Brown, S. B., R. E. Evans, and Toshiaki J. Hara. "Interrenal, Thyroidal, Carbohydrate, and Electrolyte Responses in Rainbow Trout (Salmo gairdneri) during Recovery from the Effects of Acidification." Canadian Journal of Fisheries and Aquatic Sciences 43, no. 3 (March 1, 1986): 714–18. http://dx.doi.org/10.1139/f86-087.
Анотація:
Exposure to acid-treated water (H2SO4, pH 4.76) for 21 d increased plasma glucose, protein, and cortisol levels and interrenal nuclear diameter and decreased plasma electrolytes (Na+, Cl−) and osmolality in immature rainbow trout (Salmo gairdneri). Plasma L-thyroxine (T4), 3,5,3′-triiodo-L-thyronine (T3), or their ratio (T4:T3) were not altered by the acid treatment. Following termination of acid exposure, return to control levels was achieved within 1 d by plasma protein, 3 d by plasma cortisol, glucose, sodium, chloride, and osmolality, and 7 d by interrenal nuclear diameter. Thus, within 1 wk the studied aspects of the plasma fluid compartment had recovered from the effects of acid exposure.
9
Monk, Julie A., Natalie A. Sims, Katarzyna M. Dziegielewska, Roy E. Weiss, Robert G. Ramsay, and Samantha J. Richardson. "Delayed development of specific thyroid hormone-regulated events in transthyretin null mice." American Journal of Physiology-Endocrinology and Metabolism 304, no. 1 (January 1, 2013): E23—E31. http://dx.doi.org/10.1152/ajpendo.00216.2012.
Анотація:
Thyroid hormones (THs) are vital for normal postnatal development. Extracellular TH distributor proteins create an intravascular reservoir of THs. Transthyretin (TTR) is a TH distributor protein in the circulatory system and is the only TH distributor protein synthesized in the central nervous system. We investigated the phenotype of TTR null mice during development. Total and free 3′,5′,3,5-tetraiodo-l-thyronine (T4) and free 3′,3,5-triiodo-l-thyronine (T3) in plasma were significantly reduced in 14-day-old (P14) TTR null mice. TTR null mice also displayed a delayed suckling-to-weaning transition, decreased muscle mass, delayed growth, and retarded longitudinal bone growth. In addition, ileums from postnatal day 0 (P0) TTR null mice displayed disordered architecture and contained fewer goblet cells than wild type. Protein concentrations in cerebrospinal fluid from P0 and P14 TTR null mice were higher than in age-matched wild-type mice. In contrast to the current literature based on analyses of adult TTR null mice, our results demonstrate that TTR has an important and nonredundant role in influencing the development of several organs.
10
Hercbergs, Aleck A., David H. Garfield, and Osnat Ashur-Fabian. "Triiodothyronine [T3]-induced hypothyroxinemia: Response and survival in a compassionate care cancer patient population." Journal of Clinical Oncology 30, no. 15_suppl (May 20, 2012): e19573-e19573. http://dx.doi.org/10.1200/jco.2012.30.15_suppl.e19573.
Анотація:
e19573 Background: Increased survival under chemically induced hypothyroidism has been reported in cancer patients with poor prognosis, but the associated morbidity can deter patient compliance. Acting via a receptor site upon the plasma membrane avβ3 integrin, L-thyroxine (T4) in physiological concentrations non-genomically activates mitogenesis and neo-angiogenesis of cancer cells and proliferating vascular endothelium. Occlusion of the receptor by tetraiodothyroacetic acid (tetrac), a T4 derivative, induces apoptosis, inhibits angiogenesis and enhances chemotherapy and radiation. 3, 5, 3’-Triiodo-L-thyronine (T3) in physiological concentrations is significantly less mitogenic than T4 and inhibits pituitary release of thyrotropin (TSH). Absence of TSH, but with T3 support, depletes circulating T4 without resultant hypothyroidism. Methods: 21 cancer patients at dispersed clinical sites with stage 4 solid tumors and projected limited survival received T3 [n=10] only or with methimazole (MT) [n=9]. Serum TSH, free T4 (FT4) and T3 concentrations were obtained initially, then monthly. FT4 levels below lower normal range were achieved in all patients within 3 to 12 weeks. Results: See Table. Conclusions: T3 treatment with resultant hypothyroxinemia in poor prognosis cancer patients was associated with favorable response rates in 17/19 subjects. Two others with aggressive tumors had extended survival on long-term T3. [Table: see text] [Table: see text] [Table: see text]
Дисертації з теми "3, 3', 5-triiodo-l-thyronine(t3)":
1
Hachi, Isma. "Etude structurale de biomarqueurs de neuropathologies : cas particulier de la protéine CRYM, une Cytosolic-3,3',5-triiodo-L-thyronine(T3)-Binding Protein." Grenoble, 2010. http://www.theses.fr/2010GRENV030.
Анотація:
Mon projet de thèse s'inscrit dans un vaste projet de caractérisation de protéines nouvellement identifiées dont l'expression est sélective à certaines régions du cerveau. Cette expression sélective pouvant être liée aux phénomènes de dégénérescence neuronale qui caractérisent les maladies neurodégénératives, ces protéines constituent donc des biomarqueurs potentiels. Une étude structurale et physico-chimique a été effectuée sur une dizaine de protéines, dont la protéine CRYM murine (mCRYM) qui fait parti de la famille des Cytosolic- 3,3',5-triiodo-L-thyronine(T3)-Binding Protein car elle régule la concentration en hormone thyroïdienne T3 libre dans la cellule. MCRYM appartient également à la famille des µ-crystallines et à la superfamille des µ-crystallines/Ornithines Cyclodésaminases. Les protéines présentant des homologies pour ces trois familles sont la plupart différentes par leur fonction (enzymatique ou structurale), leur localisation tissulaire et leurs caractéristiques physico-chimiques. Cette diversité est due au recrutement de gènes de la superfamille des crystallines pour diverses fonctions métaboliques tout en conservant le taxon spécifique des crystallines. Je suis parvenue à résoudre sa structure cristallographique complexée au NADP(H) et à l'hormone thyroïdienne T3 à une résolution de 1,75 Å. La protéine mCRYM est un exemple intéressant d'évolution par son appartenance à différentes familles de protéines et, à ce jour, aucune activité enzymatique n'a été identifiée. Sa caractérisation structurale et thermodynamique a donc permis de mettre en évidence les différences et les similitudes avec ses homologues enzymatiques et d'émettre des hypothèses quant à son évolution moléculaire. Ces résultats soulèvent de nouvelles questions concernant son rôle physiologique : mCRYM est-elle une enzyme ou une protéine structurale ? Comment intervient le couple redox NADPH/NADP+ pour réguler l'action génomique et/ou non génomique de l'hormone T3 ? L'hormone T3 est-il le seul ligand physiologique de CRYM dans le cerveau ?My Ph. D. Work takes part of a larger project dedicated to the characterization of proteins newly involved into selective expression of certain mouse brain regions. This selective expression being potentially linked to neuronal degeneration associated with neurodegenerative diseases, the corresponding proteins are therefore potential biomarkers. A structural and physico-chemical study has been performed on about ten proteins including CRYM of mouse (mCRYM), which belongs to the Cytosolic-3,3',5-triiodo-L-thyronine(T3)-Binding Protein family since it regulates the concentration of free thyroid hormone, T3, in the cell. MCRYM also belongs to the µ-crystallin family and to the µ-crystallins/Ornithin Cyclodesaminases superfamily. Proteins displaying sequence homologies to these three families of proteins have generally different functions (enzymatic or structural), different tissue localisation and different physico-chemical properties. This diversity is due to the recruitment of genes of the crystalline superfamily to carry different metabolic functions while preserving the taxon-specific crystallins. I have managed to resolve the crystallographic structure of mCRYM in complex with NADP(H) and the thyroid hormone, T3, to 1. 75 Å resolution. MCRYM is a very interesting evolution specimen as it belongs to a different family of proteins. However, no enzymatic function has ever been demonstrated for mCRYM. Its structural and thermodynamical characterization has revealed similitudes and divergences with the enzymatic homologues of CRYM and has allowed us to make hypothesis relative to its molecular evolution. These results raise new questions concerning the physiological role of mammalian CRYM: is CRYM an enzyme or a structural protein? How does the NADPH/NADP+ redox couple regulates the genomic and/or non genomic action of the T3 hormone? Is the T3 hormone the only physiological ligand of CRYM in the brain?
2
Hachi, Isma. "Etude structurale de biomarqueurs de neuropathologies : Cas particulier de la protéine CRYM, une Cytosolic-3,3',5-triiodo-L-thyronine(T3)-Binding Protein." Phd thesis, Université de Grenoble, 2010. http://tel.archives-ouvertes.fr/tel-00718112.
Анотація:
Mon projet de thèse s'inscrit dans un vaste projet de caractérisation de protéines nouvellement identifiées dont l'expression est sélective à certaines régions du cerveau. Cette expression sélective pouvant être liée aux phénomènes de dégénérescence neuronale qui caractérisent les maladies neurodégénératives, ces protéines constituent donc des biomarqueurs potentiels. Une étude structurale et physico-chimique a été effectuée sur une dizaine de protéines, dont la protéine CRYM murine (mCRYM) qui fait parti de la famille des Cytosolic- 3,3',5-triiodo-L-thyronine(T3)-Binding Protein car elle régule la concentration en hormone thyroïdienne T3 libre dans la cellule. mCRYM appartient également à la famille des µ-crystallines et à la superfamille des µ-crystallines/Ornithines Cyclodésaminases. Les protéines présentant des homologies pour ces trois familles sont la plupart différentes par leur fonction (enzymatique ou structurale), leur localisation tissulaire et leurs caractéristiques physico-chimiques. Cette diversité est due au recrutement de gènes de la superfamille des crystallines pour diverses fonctions métaboliques tout en conservant le taxon spécifique des crystallines. Je suis parvenue à résoudre sa structure cristallographique complexée au NADP(H) et à l'hormone thyroïdienne T3 à une résolution de 1,75 Å. La protéine mCRYM est un exemple intéressant d'évolution par son appartenance à différentes familles de protéines et, à ce jour, aucune activité enzymatique n'a été identifiée. Sa caractérisation structurale et thermodynamique a donc permis de mettre en évidence les différences et les similitudes avec ses homologues enzymatiques et d'émettre des hypothèses quant à son évolution moléculaire. Ces résultats soulèvent de nouvelles questions concernant son rôle physiologique : mCRYM est-elle une enzyme ou une protéine structurale ? Comment intervient le couple redox NADPH/NADP+ pour réguler l'action génomique et/ou non génomique de l'hormone T3 ? L'hormone T3 est-il le seul ligand physiologique de CRYM dans le cerveau ?
3
Serrar, Mostafa. "Effets croisés des régimes enrichis en stérols ou en acides biliaires et du traitement par la 3, 5,3’triiodo-L-thyronine (t3) sur les activités des enzymes microsomales hépatiques responsables du métabolisme des xénobiotiques chez le rat." Dijon, 1987. http://www.theses.fr/1987DIJOS043.
Анотація:
La supplémentation des régimes alimentaires en stérols ou en acide biliaire provoque une augmentation du taux de cholestérol et de phospholipides dans les microsomes hépatiques et une diminution du taux de malandialdéhyde. L’administration de T3 provoque l'effet inverse
4
Lehmphul, Ina. "Zelluläre Wirkung, Wirkmechanismen und Nachweisverfahren von Schilddrüsenhormonen und ihren Metaboliten." Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2015. http://dx.doi.org/10.18452/17434.
Анотація:
Schilddrüsenhormone (TH) regulieren Metabolismus und Energiestoffwechsel. Der TH‐Metabolit (THM) 3,5‐T2 (3,5‐Diiod‐L‐Thyronin) aktiviert Fett‐Oxidation und mitochondriale Atmung. Der THM 3‐Iodothyronamin (3‐T1AM) beeinflusst zusätzlich glukoregulatorische Prozesse. THM können zur Reduktion von Körperfett beitragen. Um 3,5‐T2 im humanen Serum nachzuweisen sollte ein Immunoassay aufgebaut, validiert und angewendet werden. In intakten hepatozellulären (HepG2) sowie pankreatischen ß‐Zellen (MIN6) sollte untersucht werden ob THM durch Modulation der mitochondrialen Aktivität die zelluläre Substratverstoffwechslung (3,5‐T2) und Insulinsekretion (3‐T1AM) regulieren können. Der Immunoassay ist sensitiv, spezifisch und misst zuverlässig 3,5‐T2 im humanen Serum. Hyper‐ und Hypothyreose zeigen vergleichbare 3,5‐T2 Konzentrationen, jedoch akkumuliert 3,5‐T2 bei sekundären Erkrankungen der Schilddrüse und athyreoten Patienten unter Thyroxin‐Supplementation. In HepG2‐Zellen konnte die Aktivierung der mitochondrialen Atmung durch 3,3‘,5‐Triiod‐L‐Thyronin (T3), jedoch nicht durch 3,5‐T2 stimuliert werden. Die Expression von TH‐transporters (THT) war gering verglichen mit Maus‐Hepatozyten. MIN6 exprimiert THT vergleichbar mit Langerhansschen Inselzellen der Maus. 3‐T1AM wird in die Zelle aufgenommen, zu 3‐Iodothyroessigsäure (TA1) metabolisiert, und wieder exportiert. Nach 3‐T1AM Gabe ist die mitochondriale ATP‐Produktion sowie die Glukose‐stimulierte Insulinsekretion (GSIS) vermindert. 3,5‐T2 zirkuliert in euthyreoten Individuen, ist nicht an der zentralen Regulation der TH‐Achse beteiligt, wird extrathyroidal gebildet und niedrige T3‐Werte können durch erhöhtes 3,5‐T2 erklärt werden. HepG2 erwies sich als ungeeignetes Zellmodell, da wenige THT vorhanden sind, 3,5‐T2 die Plasmamembran wahrscheinlich nicht passieren kann und damit die Aktivierung der Mitochondrien aus bleibt. In MIN6 wurde gezeigt, dass die GSIS nicht ausschließlich an der Plasmamembran durch 3‐T1AM reguliert wird.Thyroid hormones (TH) regulate metabolism and energy metabolism. The TH‐metabolite (THM) 3,5‐T2 (3,5‐diiodo‐L‐thyronine) activates fat oxidation and mitochondrial respiration. The THM 3‐T1AM (3‐iodothyronamine) influences in addition glucoregulatory processes. THM may support reduction in body fat mass. It was the idea to establish, validate and apply an immunoassay to determine 3,5‐T2 in human serum. Using intact hepatocellular (HepG2) as well as pancreatic ß‐cells (MIN6) it should be tested if THM can modulate mitochondrial activity, resulting in increased cellular substrate usage (3,5‐T2) as well as decreased insulin secreation (3‐T1AM). The established immunoassay is sensitive, specific and detects precisely 3,5‐T2 in human serum. Hyper‐ and hypothyroidism shows similar 3,5‐T2 concentrations, although 3,5‐T2 accumulates in secondary thyroidal illness as well as in athyreotic patients under thyroxine‐supplementation. Using HepG2 cells, mitochondrial respiration was stimulated by 3,3‘,5‐triiodo‐L‐thyronine (T3), but 3,5‐T2 had no effect. Expression of TH‐transporters (THT) was low compared to murine hepatocytes. In contrast, MIN6 express THT comparable to murine Langerhans islets. 3‐T1AM is taken up by the cell, metabolized to 3‐iodothyroacetic acid (TA1) and following export. After 3‐T1AM application mitochondrial ATP‐production as well as glucose‐stimulated insulin secretion (GSIS) was reduced. 3,5‐T2 circulates in euthyroid individuals, is not involved in central regulation of TH‐axis, is produced extrathyroidally and low T3 values can be explained by increased 3,5‐T2. HepG2 was shown to be an inappropriate cellmodel, because THT are merely expressed, suggesting that 3,5‐T2 is not able to pass the plasma membrane, thereby preventing mitochondrial activation. In addition, it was shown in MIN6 cells, that GSIS is not exclusively regulated at the plasma membrane level via 3‐T1AM.
Частини книг з теми "3, 3', 5-triiodo-l-thyronine(t3)":
1
Roche, Jean, Raymond Michel, and Pierre Jouan. "On the Presence of 3:5:3′-Triiodothyro-Acetic Acid and 3:3′-Diiodothyronine in Rat Muscle and Kidney after Administration of 3:5:3′-Triiodo-L-Thyronine." In Ciba Foundation Symposium - Regulation and Mode of Action of Thyroid Hormones (Colloquia on Endocrinology, Vol. 10), 168–81. Chichester, UK: John Wiley & Sons, Ltd., 2008. http://dx.doi.org/10.1002/9780470719022.ch12.