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Type: Artigo de periódico
Title: Endurance Training Activates Amp-activated Protein Kinase, Increases Expression Of Uncoupling Protein 2 And Reduces Insulin Secretion From Rat Pancreatic Islets.
Author: Calegari, Vivian Cristine
Zoppi, Claudio Cesar
Rezende, Luiz Fernando
Silveira, Leonardo Reis
Carneiro, Everardo Magalhães
Boschero, Antonio Carlos
Abstract: 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 β-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-γ coactivator-1-α (PGC-1α) 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-1α protein expression. In conclusion, chronic endurance exercise induces adaptations in β-cells leading to a reduction in GIIS, probably by activating the AMPK signaling pathway.
Subject: Amp-activated Protein Kinases
Calcium-calmodulin-dependent Protein Kinase Type 2
Glucose Transporter Type 2
Ion Channels
Islets Of Langerhans
Mitochondrial Proteins
Muscle, Skeletal
Physical Conditioning, Animal
Physical Endurance
Rna-binding Proteins
Rats, Wistar
Transcription Factors
Citation: The Journal Of Endocrinology. v. 208, n. 3, p. 257-64, 2011-Mar.
Rights: fechado
Identifier DOI: 10.1530/JOE-10-0450
Date Issue: 2011
Appears in Collections:Unicamp - Artigos e Outros Documentos

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