RESUMO
Nonalcoholic fatty liver disease (NAFLD) is characterized by fat accumulation in the liver and is associated with obesity and insulin resistance. Activin A is a member of the transforming growth factor beta (TGF)-β superfamily and inhibits hepatocyte growth. Follistatin antagonizes the biological actions of activin. Exercise is an important therapeutic strategy to reduce the metabolic effects of obesity. We evaluated the pattern of activin A and follistatin liver expression in obese rats subjected to swimming exercise. Control rats (C) and high-fat (HF) diet-fed rats were randomly assigned to a swimming training group (C-Swim and HF-Swim) or a sedentary group (C-Sed and HF-Sed). Activin βA subunit mRNA expression was significantly higher in HF-Swim than in HF-Sed rats. Follistatin mRNA expression was significantly lower in C-Swim and HF-Swim than in either C-Sed or HF-Sed animals. There was no evidence of steatosis or inflammation in C rats. In contrast, in HF animals the severity of steatosis ranged from grade 1 to grade 3. The extent of liver parenchyma damage was less in HF-Swim animals, with the severity of steatosis ranging from grade 0 to grade 1. These data showed that exercise may reduce the deleterious effects of a high-fat diet on the liver, suggesting that the local expression of activin-follistatin may be involved.
Assuntos
Animais , Masculino , Ativinas/metabolismo , Terapia por Exercício , Folistatina/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Obesidade/terapia , Esforço Físico , Peso Corporal , Glicemia/análise , Modelos Animais de Doenças , Dieta Hiperlipídica/efeitos adversos , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Expressão Gênica , Hepatopatia Gordurosa não Alcoólica/terapia , Obesidade/metabolismo , Distribuição Aleatória , Ratos Wistar , RNA Mensageiro/metabolismo , NataçãoRESUMO
Nonalcoholic fatty liver disease (NAFLD) is characterized by fat accumulation in the liver and is associated with obesity and insulin resistance. Activin A is a member of the transforming growth factor beta (TGF)-ß superfamily and inhibits hepatocyte growth. Follistatin antagonizes the biological actions of activin. Exercise is an important therapeutic strategy to reduce the metabolic effects of obesity. We evaluated the pattern of activin A and follistatin liver expression in obese rats subjected to swimming exercise. Control rats (C) and high-fat (HF) diet-fed rats were randomly assigned to a swimming training group (C-Swim and HF-Swim) or a sedentary group (C-Sed and HF-Sed). Activin ßA subunit mRNA expression was significantly higher in HF-Swim than in HF-Sed rats. Follistatin mRNA expression was significantly lower in C-Swim and HF-Swim than in either C-Sed or HF-Sed animals. There was no evidence of steatosis or inflammation in C rats. In contrast, in HF animals the severity of steatosis ranged from grade 1 to grade 3. The extent of liver parenchyma damage was less in HF-Swim animals, with the severity of steatosis ranging from grade 0 to grade 1. These data showed that exercise may reduce the deleterious effects of a high-fat diet on the liver, suggesting that the local expression of activin-follistatin may be involved.
Assuntos
Ativinas/metabolismo , Terapia por Exercício , Folistatina/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Obesidade/terapia , Esforço Físico , Animais , Glicemia/análise , Peso Corporal , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Expressão Gênica , Masculino , Hepatopatia Gordurosa não Alcoólica/terapia , Obesidade/metabolismo , RNA Mensageiro/metabolismo , Distribuição Aleatória , Ratos Wistar , NataçãoRESUMO
We evaluated the expression of MSTN and ActRIIB mRNA in muscle and adipose tissue in diet-induced obesity and insulin resistance in rats subjected to exercise. There was no difference in the expression of MSTN between exercised and sedentary high-fat fed rats in muscle after swimming training. The expression of ActRIIB mRNA in muscle was not significantly different among the groups. In BAT, MSTN mRNA expression was higher in exercised high-fat fed group (EHF) compared with sedentary high-fat fed group (SHF). ActRIIB mRNA expression in BAT was higher in EHF compared with SHF. In mesenteric fat, MSTN mRNA was lower in EHF compared with SHF and ActRIIB mRNA was lower in EHF compared with SHF. In conclusion, the results demonstrate that the expression of MSTN and ActRIIB mRNA changes in both adipose tissue and skeletal muscle in diet-induced obese and exercised rats and suggest the participation of MSTN in energy homeostasis.