Changes of expression of protein tyrosine phosphatase 1B in rats with diet-induced obesity

Objective To investigate the changes of expression of protein tyrosine phosphatase 1B(PTP1B)in rats with diet-induced obesity,and understand the role of PTP1B in the development of insulin resistance.Methods Twenty male SD rats were divided into two groups of taking normal chow(group NC)and high-fat diet(group HF)with 10 rats each.Eight weeks later,body weight,fasting glucose,fasting insulin and lipid profile were determined and HOMA-IR was calculated.PTP1B levels in muscle,liver and pancreas were measured by immunohistochemical method.ResultsRats of group HF showed significantly the body weight gain(P0.01)and insulin resistance(HOMA-IR was 8.58±3.37 for group HF and 3.46±2.21 for group NC,P0.01).Compared with group NC,the levels of PTP1B in the muscle,liver and pancreas were significantly higher in group HF(P0.01).Conclusion Obese rats with insulin resistance have been induced successfully with high-fat diet and the state of insulin resistance of obese rats is correlated with the increased levels of PTP1B in the muscle,liver and pancreas.