Endurance training activates AMP-activated protein kinase, increases expression of uncoupling protein 2 and reduces insulin secretion from rat pancreatic islets

Autor(es)

Calegari, Vivian Cristine ^[1] ; Zoppi, Claudio Cesar ^[1] ; Rezende, Luiz Fernando ^[1] ; Silveira, Leonardo Reis ^[2] ; Carneiro, Everardo Magalhaes ^[1] ; Boschero, Antonio Carlos ^[1]

Afiliação do(s) autor(es)

^[1] State Univ Campinas UNICAMP, Endocrine Pancreas & Metab Lab, Dept Anat Cellular Biol & Physiol & Biophys, Inst Biol, BR-13083865 Campinas, SP - Brazil

^[2] Univ Sao Paulo, Dept Biochem & Immunol, Fac Med Ribeirao Preto, Sch Phys Educ & Sports, BR-14040900 Ribeirao Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Endocrinology; v. 208, n. 3, p. 257-264, MAR 2011.
• Citações Web of Science: 36

Resumo

Endurance exercise is known to enhance peripheral insulin sensitivity and reduce insulin secretion. However, it is unknown whether the latter effect is due to the reduction in plasma substrate availability or alterations in beta-cell secretory machinery. Here, we tested the hypothesis that endurance exercise reduces insulin secretion by altering the intracellular energy-sensitive AMP-activated kinase (AMPK) signaling pathway. Male Wistar rats were submitted to endurance protocol training one, three, or five times per week, over 8 weeks. After that, pancreatic islets were isolated, and glucose-induced insulin secretion (GIIS), glucose transporter 2 (GLUT2) protein content, total and phosphorylated calmodulin kinase kinase (CaMKII), and AMPK levels as well as peroxisome proliferator-activated receptor-gamma coactivator-1-alpha (PGC-1 alpha) and uncoupling protein 2 (UCP2) content were measured. After 8 weeks, chronic endurance exercise reduced GIIS in a dose-response manner proportionally to weekly exercise frequency. Contrariwise, increases in GLUT2 protein content, CaMKII and AMPK phosphorylation levels were observed. These alterations were accompanied by an increase in UCP2 content, probably mediated by an enhancement in PGC-1 alpha protein expression. In conclusion, chronic endurance exercise induces adaptations in beta-cells leading to a reduction in GIIS, probably by activating the AMPK signaling pathway. Journal of Endocrinology (2011) 208, 257-264 (AU)

• Processo FAPESP: 07/50365-4 - Estudo dos mecanismos de destruição das células beta pancreáticas durante a instalação do Diabetes Mellitus (DM2): busca de estratégias para a inibição desse processo bem como para a recuperação da massa insular em diferentes modelos animais
• Beneficiário: Antonio Carlos Boschiero
• Modalidade de apoio: Auxílio à Pesquisa - Temático