Endocrine Abstracts

Introduction: Previous data shows that weight reduction decreases serum retinol binding protein-4 (RBP4) level. But it is not yet clear whether decreases in body weight resulted from exercise, will be accompanied by the changes of RBP4 protein expression in liver and adipose tissues in type 2 diabetes. Thus we designed this study to evaluate the ability of 7 weeks exercise to reverse the changes in body weight, insulin resistance (IR), serum RBP4 and its expression in liver and adipose tissue in high fat diet- STZ induced type 2 diabetic rats.

Method: Age matched male wistar rats were randomly divided to one of four groups: control (C), control trained (CT), diabetic untrained (DU) and diabetic trained (DT) (n=6 each group). A combination of high fat diet (HFD) and STZ injection were used to induce diabetes in DU and DT groups. Finally both CT and DT groups underwent a 7 weeks treadmill running at low speed. Rats were 18-week-old when tested. Serum RBP4 and tissue RBP4 protein expression were measured using Elisa and western blot respectively.

Results: Exercise causes a significant decrease in body weight in DT group. Moreover exercise leads to reduction in IR and serum concentration of RBP4. Although these values are significantly lower in DT group compared to DU group but still did not reach to the level of the C group. Exercise also significantly decreased RBP4 protein expression in liver and visceral fat tissue. However this reduction also didn’t reach to the levels of the C group.

Conclusion: These findings suggest that despite completely normalizing body weight, exercise partially improved IR, serum RBP4 and its protein expression in liver and visceral fat in diabetic rat induced by HFD and STZ injection.