Acute exercise decreases PTP-1B protein level and improves insulin signaling in the liver of old rats

Autor(es)

de Moura, Leandro Pereira ^[1] ; Souza Pauli, Luciana Santos ^[2] ; Cintra, Dennys Esper ^[2] ; de Souza, Claudio Teodoro ^[3] ; Ramos da Silva, Adelino Sanchez ^[4] ; Marinho, Rodolfo ^[2] ; Rostom de Melo, Maria Alice ^[1] ; Ropelle, Eduardo Rochete ^[2] ; Pauli, Jose Rodrigo ^{[1, 2, 5]}

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista, UNESP, Curso Posgrad Ciencias Motricidade Humana, Rio Claro, SP - Brazil

^[2] Univ Estadual Campinas, UNICAMP, Fac Ciencias Aplicadas, Curso Posgrad Nutr Esporte & Metab, Limeira, SP - Brazil

^[3] Univ Sao Paulo, Escola Educ Fis & Esporte, BR-14049 Ribeirao Preto, SP - Brazil

^[4] Univ Extremo Sul Catarinense, Lab Bioquim & Fisiol, Circiuma, SC - Brazil

^[5] FCA UNICAMP, Curso Ciencias Esporte, Limeira, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: IMMUNITY & AGEING; v. 10, FEB 25 2013.
• Citações Web of Science: 13

Resumo

It is now commonly accepted that chronic inflammation associated with obesity during aging induces insulin resistance in the liver. In the present study, we investigated whether the improvement in insulin sensitivity and insulin signaling, mediated by acute exercise, could be associated with modulation of protein-tyrosine phosphatase 1B (PTP-1B) in the liver of old rats. Aging rats were subjected to swimming for two 1.5-h long bouts, separated by a 45 min rest period. Sixteen hours after the exercise, the rats were sacrificed and proteins from the insulin signaling pathway were analyzed by immunoblotting. Our results show that the fat mass was increased in old rats. The reduction in glucose disappearance rate (Kitt) observed in aged rats was restored 16 h after exercise. Aging increased the content of PTP-1B and attenuated insulin signaling in the liver of rats, a phenomenon that was reversed by exercise. Aging rats also increased the IR beta/PTP-1B and IRS-1/PTP-1B association in the liver when compared with young rats. Conversely, in the liver of exercised old rats, IR beta/PTP-1B and IRS-1/PTP-1B association was markedly decreased. Moreover, in the hepatic tissue of old rats, the insulin signalling was decreased and PEPCK and G6Pase levels were increased when compared with young rats. Interestingly, 16 h after acute exercise, the PEPCK and G6Pase protein level were decreased in the old exercised group. These results provide new insights into the mechanisms by which exercise restores insulin signalling in liver during aging. (AU)

• Processo FAPESP: 10/12091-2 - Efeitos do treinamento físico sobre o processo inflamatório e apoptótico em neurônios hipotalâmicos de controle da fome em camundongos obesos induzidos por dieta hiperlipídica
• Beneficiário: José Rodrigo Pauli
• Modalidade de apoio: Auxílio à Pesquisa - Regular