RESUMO
Fed with high-fat diet and assessed by hyperinsulinemia-euglycemia clamp technique, rat models with insulin resistance were successfully induced. Compared with normal chow group ( NC ), serum concentrations of free-fatty acids(FFAs) and baseline insulin in high-fat diet group(HF) was higher( P＜0.05 ), the average glucose infusion rate from 60 to 120 min( GIR60-120 ) was lower( P＜0.01 ), and the expression of p-IRE-lα in the liver was higher( P＜0.05 ). Furthermore, the expression of p-IRE-1α in the liver was positvely correlated with the serum concentration of FFAs. All these data indicate that high-fat diet may induce endoplasmic reticulum stress in the liver by elevating serum concentration of FFAs, and may participate in the genesis of insulin resistance via p-IRE-1α.
RESUMO
Objective To investigate the effect of swimming exercise on insulin sensitivity and interleukin-1 beta(IL-1β)mRNA expression in muscle tissue of insulin-resistant (IR) rats induced by high-fat diet.Methods The IR rat model was induced by high-fat diet feeding for 10 weeks and assessed by hyperinsulinemic-euglycemic clamp technique (HEC). The rats were divided into the fllowing three groups: normal group without exercise, IR groups with and without swimming exercise. After 4 weeks swimming excersie, insulin sensitivity and serum IL-1β levels were measured.Results Glucose infusion rate (GIR) of the IR rats was significantly elevated than that of non-exercise IR rats (P<0.01). Moreover, serum IL-1β levels were reduced markedly in IR rats (P<0.01). Conclusion High-fat diet feeding can partly reverse IR of rats to normal value. Swimming exercise improves insulin sensitivity and reduces the levels of IL-1β in IR rats induced by high-fat diet.