Effect Of Swimming Training On The Expression Of IL-6 And PPAR-γ In Rats With Insulin Resistance

OBJECTIVES: 1) to investigate the effect of exercise (swimming training) on the expression of IL-6 and PPAR-γin rats with insulin resistance; 2) to explore the mechanisms that why exercise could improve the insulin resistance.METHODS: Forty-nine male Sprague-Dawiey rats were randomly assigned to two groups: The normal diet group(control group, n=10) and the high-fat/high-sucrose diet group(n=-40). After six weeks, the serum level of FBG and FINS were measured and ISI was calculated to confirm the establishment of insulin resistance model. Then the thirty-four rats with insulin resistance were randomly assigned to four groups:①continue the high-fat/high-sucrose diet (model group, n=9);②a high-fat/high-sucrose diet combined with metformin (metformin group, n=8);③a high-fat/high-sucrose diet combined with swimming training (exercise group, n=9); or④the high-fat/high-sucrose with metformin and swimming training (combination group, n=8). Alter six weeks intervention, the serum level of Interleukin-6 (IL-6) were measured by enzyme linked immunosorbent assay (ELISA); and the expression of PPAR-γprotein in adipose and liver tissue were measured by immunohisto-chemistry; the expression of peroxisome proliferatorsactivated receptor gamma (PPAR-γ) and IL-6 mRNA in adipose and liver tissue were measured by RT-PCR.RESULTS: After fed with the high-fat/high-sucrose for six weeks, compared with the control group, the serum level of FBG and FINS were significantly increased, and ISI was significantly decreased in the model group (p＜0.05 all). After six weeks of intervention, compared with control group, the serum level of lipids, FBG , FINS, IL-6 and body weight, visceral fat, diameter of adipocyte as well as the expression of PPAR-γ, IL-6 mRNA and PPAR-γprotein in adipose and liver tissue were significantly increased while ISI was significantly further decreased in the model group (p＜0.05 all).Compared with model group, the serum content of lipids, FBG, FINS, IL-6 and body weight, visceral fat as well as the expression of IL-6 mRNA in adipose and liver tissue were significantly lower (p＜0.05 all); the ISI was significantly higher in the metformin group, exercise group and combination group (p＜0.05). In addition, the diameter of adipocyte was decreased, the level of PPAR-γmRNA and protein in adipose and liver tissue were significantly increased in the exercise group and combination group compared with those in the model group (p＜0.05 all). No significant changes were observed between the metformin group and the model group in the expression of PPAR-γmRNA and protein, and the diameter of adipocyte.CONCLUSION:①swimming training can improve insulin resistance②swimming training could not only lower the level of IL-6, but also increase the expression of PPAR-ywhich might be the mechanisms that exercise could improve insulin resistance.