Effects of different intensities of physical exercise on insulin sensitivity and protein kinase B/Akt activity in skeletal muscle of obese mice.

Rodolfo Marinho,Luciana Santos Souza Pauli,Claudio Teodoro De Souza,Bárbara De Almeida Rodrigues,Dennys Esper Corrêa Cintra,Adelino Sanchez Ramos Da Silva,José Rodrigo Pauli,Leandro Pereira De Moura,Eduardo Rochete Ropelle,Eloize Cristina Chiarreotto Ropelle

doi:10.1590/s1679-45082014ao2881

Abstract

ABSTRACTObjective:To investigate the effects of different intensities of acute exercise on insulin sensitivity and protein kinase B/Akt activity in skeletal muscle of obese mice.Methods:Swiss mice were randomly divided into four groups, and fed either a standard diet (control group) or high fat diet (obese sedentary group and obese exercise group 1 and 2) for 12 weeks. Two different exercise protocols were used: swimming for 1 hour with or without an overload of 5% body weight. The insulin tolerance test was performed to estimate whole-body sensitivity. Western blot technique was used to determine protein levels of protein kinase B/Akt and phosphorylation by protein Kinase B/Akt in mice skeletal muscle.Results:A single bout of exercise inhibited the high fat diet-induced insulin resistance. There was increase in phosphorylation by protein kinase B/Akt serine, improve in insulin signaling and reduce of fasting glucose in mice that swam for 1 hour without overload and mice that swan for 1 hour with overload of 5%. However, no significant differences were seen between exercised groups.Conclusion:Regardless of intensity, aerobic exercise was able to improve insulin sensitivity and phosphorylation by protein kinase B/Ak, and proved to be a good form of treatment and prevention of type 2 diabetes.

Highlights

Physical exercise increases insulin sensitivity independently of body mass reduction and changes in body composition.[1]. The major effect of exercise is the increase in intracellular proteins expression of insulin signaling pathway especially the glucose transport in skeletal muscle.[1,2,3]
That situation revealed the importance of this isoform for cellular survival.[6]. Akt2 knockout mice developed characteristics of type 2 diabetes mellitus that were crucial for maintenance of glycemia
This study investigated the effects of different intensities of acute exercise on insulin sensibility and Akt phosphorylation in skeletal muscle of obese mice

Summary

Introduction

Physical exercise increases insulin sensitivity independently of body mass reduction and changes in body composition.[1]. Obese individuals and resistant to insulin have as common characteristics the problem in insulin signaling due to subclinical inflammatory process. This process shows a decrease in action of this hormone in target cells and is influenced by the presence of fasting hyperglycemia and hyperinsulinemia. Such metabolic changes are associated with a decrease in glucose uptake by skeletal muscle in response to insulin.[4]. That situation revealed the importance of this isoform for cellular survival.[6] Akt knockout mice developed characteristics of type 2 diabetes mellitus that were crucial for maintenance of glycemia. Animals with protein Akt absence had an impairment in brain development.[5,6,7,8]

Methods

Results

Conclusion