Abstract: Objective To observe the expression of GRP78 mRNA in visceral obese of rats fed with high fat diet in order to explore its effects on insulin resistance. Methods Thirty Wistar rats were randomly divided into two groups: normal chow group (NC) was fed with free normal chow for 10 weeks; high fat group (HF) was fed with high fat diet for 10 weeks. The expression of GRP78 mRNA was detected by real time PCR. The total cholesterol triglyceride，the rate of visceral fat (epididymal fat) vs. body weight and fasting insulin were also detected.ResuIts (1) Glucose infusion rate (GIR) in HF group was obviously lower than that in NC group (P＜0.01). Rats in HF group had an elevation of fasting insulin compared with NC group (P＜0.05). (2) The expression of GRP78 mRNA was significantly higher in HF group than that in NC group (P＜0.01). (3) Rats in HF group had an obviously elevation of fasting insulin ,total cholesterol and triglyceride compared with NC group Conclusion After 10 weeks fed with high fat diet, the insulin resistant animal models was established. High fat diet can induce the expression of GRP78 mRNA in visceral obese tissue.

Key words: Endoplasmic reticulum stress, Insulin resistance, GRP78, Obese tissue