Busca avançada
Ano de início
(Referência obtida automaticamente do SciELO, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Hypercaloric cafeteria-like diet induced UCP3 gene expression in skeletal muscle is impaired by hypothyroidism

Texto completo
Christoffolete, M. A. ; Moriscot, A. S. [2]
Número total de Autores: 2
Tipo de documento: Comunicação Científica
Fonte: Brazilian Journal of Medical and Biological Research; v. 37, n. 6, p. 923-927, Jun. 2004.
Área do conhecimento: Ciências Biológicas - Fisiologia
Assunto(s):Hormônios tireóideos   Hipotireoidismo

The uncoupling protein UCP3 belongs to a family of mitochondrial carriers located in the inner mitochondrial membrane of certain cell types. It is expressed almost exclusively at high levels in skeletal muscle and its physiological role has not been fully determined in this tissue. In the present study we have addressed the possible interaction between ahypercaloric diet and thyroid hormone (T3), which are strong stimulators of UCP3 gene expression in skeletal muscle. Male Wistar rats weighing 180 ± 20 g were rendered hypothyroid by thyroidectomy and the addition of methimazole (0.05%; w/v) to drinking water after surgery. The rats were fed a hypercaloric cafeteria diet (68% carbohydrates, 13% protein and 18% lipids) for 10 days and sacrificed by decapitation. Subsequently, the gastrocnemius muscle was dissected, total RNA was isolated with Trizol™ and UCP3 gene expression was determined by Northern blotting using a specific probe. Statistical analysis was performed by one-way analysis of variance (ANOVA) followed by the Student-Newman-Keuls post-test. Skeletal muscle UCP3 gene expression was decreased by 60% in hypothyroid rats and UCP3 mRNA expression was increased 70% in euthyroid cafeteria-fed rats compared to euthyroid chow-fed animals, confirming previous studies. Interestingly, the cafeteria diet was unable to stimulate UCP3 gene expression in hypothyroid animals (40% lower as compared to euthyroid cafeteria-fed animals). The results show that a hypercaloric diet is a strong stimulator of UCP3 gene expression in skeletal muscle and requires T3 for an adequate action. (AU)

Processo FAPESP: 98/10498-4 - Regulação endócrino-metabólica do gene da UCP3 in vivo e in vitro
Beneficiário:Marcelo Augusto Christoffolete
Linha de fomento: Bolsas no Brasil - Mestrado
Processo FAPESP: 97/00650-0 - Acao molecular do hormonio tiroideano sobre a expressao do gene da serca-2.
Beneficiário:Anselmo Sigari Moriscot
Linha de fomento: Auxílio à Pesquisa - Regular