Title:	The thyroid hormone receptor β-selective agonist GC-1 does not affect tolerance to exercise in hypothyroid rats
Authors:	Gonçalves, Alexandre Tolentino, Chineyder Corrêa Souza, Fernanda Rodrigues de Huss, Juliana Carla da Costa Zinato, Karolinne de Lourdes Lopes, Leandro Teixeira Paranhos Furlanetto Júnior, Roberto Neves, Francisco de Assis Rocha
Assunto::	Exercícios físicos Tireóide Hipotiroidismo
Issue Date:	Apr-2015
Publisher:	Sociedade Brasileira de Endocrinologia e Metabologia
Citation:	GONÇALVES, Alexandre et al. The thyroid hormone receptor β-selective agonist GC-1 does not affect tolerance to exercise in hypothyroid rats. Archives of Endocrinology and Metabolism, São Paulo, v. 59, n. 2, p. 141-147, abr. 2015. Disponível em: <http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2359-39972015000200141&lng=en&nrm=iso>. Acesso em: 16 mar. 2018. doi: http://dx.doi.org/10.1590/2359-3997000000027.
Abstract:	Objective: investigate the effect of GC-1 on tolerance to exercise in rats with experimental hypothyroidism. Materials and methods: hypothyroidism was induced with methimazole sodium and perchlorate treatment. Six groups with eight animals were studied: control group (C), hypothyroid group without treatment (HYPO); hypothyroidism treated with physiological doses of tetraiodothyronine (T4) or 10 times higher (10×T4); hypothyroidism treated with equal molar doses of GC-1 (GC-1) or 10 times higher (10×GC-1). After eight weeks, each animal underwent an exercise tolerance test by measuring the time (seconds), in which the rats were swimming with a load attached to their tails without being submerging for more than 10 sec. After the test, the animals were killed, and blood samples were collected for biochemical analysis, and the heart and soleus muscle were removed for weighing and morphometric analysis of the cardiomyocyte. Results: hypothyroidism significantly reduced tolerance to exercise and, treatment with GC-1 1× or T4 in physiological doses recover tolerance test to normal parameters. However, high doses of T4 also decreased tolerance to physical exercise. Conversely, ten times higher doses of GC-1 did not impair tolerance to exercise. Interestingly, hypothyroidism, treated or not with T4 in a physiological range, GC-1 or even high doses of GC-1 (10X) did not change cardiomyocyte diameters and relative weight of the soleus muscle. In contrast, higher doses of T4 significantly increased cardiomyocyte diameter and induced atrophy of the soleus muscle. Conclusion: unlike T4, GC-1 in high doses did not modify tolerance to physical exercise in the rats with hypothyroidism.
Licença::	Archives of Endocrinology and Metabolism - This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY NC 3.0). Fonte: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2359-39972015000200141&lng=en&nrm=iso. Acesso em: 16 mar. 2018.
DOI:	http://dx.doi.org/10.1590/2359-3997000000027
Appears in Collections:	Artigos publicados em periódicos e afins

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.