肥胖大鼠胰岛蛋白酪氨酸磷酸酶1B表达与胰岛分泌功能研究

Relationship between the expression of protein-tyrosine phosphatase 1B and islet function in obese rats

目的分离培养高脂饮食诱导肥胖大鼠模型胰岛,检测其蛋白酪氨酸磷酸酶1B(protein tyrosine phosphatase 1B,PTP1B)表达及胰岛分泌功能。方法 SD大鼠40只随机分为正常饮食组和高脂饮食组各20只,喂养8周后检测体质量、血糖、血胰岛素、血脂,分离大鼠胰岛细胞,行葡萄糖刺激胰岛素分泌判断β细胞功能,Western法检测PTP1B表达。结果高脂饮食组大鼠体质量、血脂、血胰岛素水平、胰岛素抵抗指数均较正常饮食组明显升高(P<0.01),正常饮食组大鼠胰岛给予葡萄糖刺激后胰岛素分泌是基线的(6.7±1.3)倍,高脂饮食组为(2.2±0.3)倍,二者比较差异有统计学意义(P<0.01);高脂饮食组大鼠胰岛PTP1B表达明显高于正常饮食组。结论肥胖大鼠胰岛中PTP1B表达增加,葡萄糖刺激胰岛素分泌功能受损。

Objective To obtain high-fat diet induced isolated islets, and detect the expression of protein tyrosine phosphatase 1B （PTP1B） in islets and insulin secretion function. Methods Forty 8 week-old male SD rats were randomly divided into ＊wo groups： standard rodent chow （RD） group and high fat diet （HFD） group, with 20 rats in each group. After 8 weeks, the body mass, serum glucose level, insulin level and lipid level were measured. Islets were isolated. The function of purified islets was determined by glucose-stimulated insulin secretion （GSIS） and the expression of PTP1B in islets was determined with Western blot. Results The body mass, lipid level, insulin level and homeostasis model assessment of insulin resistance index increased significantly in HFD group in comparison wish RD group （P〈0.01）. GSIS was （2.2±0.3） and （6.7±1.3） times higher in HFD group and RD group than the baseline （P〈0.01）. PTP1B expression in isolated islets of HFD group was higher than that in RD group （P〈0.01）. Conclusion The expression of PTP1B increases significantly and GSIS function decreases in islets of obese rats.