The effects of different doses of exercise and caloric restriction on insulin receptor substrate-1 in obese male rats

Abstract

Aim and backgrounds: sedentary lifestyle and high-calorie foods lead to obesity, hence the aim of the study was to investigate the effects of different doses of exercise and caloric restriction on insulin receptor substrate-1 in obese male rats. Methods and materials: 48, eight-week-old male Wistar rats (190 ± 16 g) fed high-fat palate for seventeen weeks. After obesity induction, the obesity group was randomly assigned to one of the six groups: EXE, CR, EXCR1, EXCR2, and EXCR3 as experimental groups and OC as the control group. Then 10% of food intake was reduced. Exercise intensity was adjusted about 70-75% vo2max, 28 m/min for 48 to 55 minute. Negative energy balance was applied through caloric restriction (CR) (6d/w), exercise training (EXE) (6d/w), and in three combinations: EXCR1 (2d/w exercise + 4d/w CR), EXCR2 (3d/w exercise + 3d/w CR) and EXCR3 (4d/w exercise + 2d/w CR) for two month. One way ANOVA and Tukey post-hoc was applied for Data analysis by SPSS version 16 (p<0.05). Results: IRS-1 mRNA expression was significantly higher in CR in comparison to OC (p=0.024). Also EXCR2 IRS-1significantly increased comparing to OC (p=0.033).weight in CR, EXCR1, 2,3 were significantly reduced compared to OC or HC. Conclusion: 10% of negative energy balance in forms of caloric restriction per se or in conjunction with exercise can provoke mRNA expression of insulin substrate receptor-1 that may lead to insulin sensitivity improvement.

Keywords

• obesity
• exercise
• caloric restriction
• insulin receptor substrate-1
• rat