高脂饮食诱导肥胖模型大鼠骨骼肌组织蛋白酪氨酸磷酸酯酶1B和胰岛素受体底物2的表达

背景：外周组织的胰岛素抵抗是2型糖尿病的主要病因。目的：观察高脂饮食诱导的肥胖大鼠骨骼肌中蛋白酪氨酸磷酸酯酶1B和胰岛素受体底物2的表达。方法：将20只SD大鼠随机等分为对照组和高脂组,分别给予常规饲料和高脂饲料喂养12周。结果和结论：与对照组相比,高脂组大鼠胰岛素敏感指数显著降低(P < 0.01),大鼠葡萄糖耐量受损,胰岛素释放试验提示葡萄糖刺激的胰岛素第一时相分泌受损,骨骼肌组织中蛋白酪氨酸磷酸酯酶1B蛋白表达水平明显增加(P < 0.01),骨骼肌中胰岛素诱导的胰岛素受体底物2磷酸化程度降低(P < 0.01)。提示高脂饮食诱导的肥胖大鼠骨骼肌中蛋白酪氨酸磷酸酯酶1B蛋白表达量升高,使胰岛素诱导的胰岛素受体底物2磷酸化程度降低,可能是肥胖导致胰岛素抵抗的机制之一。 关键词：肥胖;蛋白酪氨酸磷酸酶1B;胰岛素受体底物2;骨骼肌;胰岛素抵抗doi:10.3969/j.issn.1673-8225.2012.20.020

Expression of protein-tyrosine phosphatase 1B and insulin receptor substrate 2 in the skeletal muscle of rats with insulin resistance induced by high-fat diet

BACKGROUND: Insulin resistance in the peripheral tissue is a major cause of type 2 diabetes mellitus. OBJECTIVE: To observe the expression of protein tyrosine phosphatase 1B (PTP-1B) and insulin receptor substrate 2 (IRS-2) in the skeletal muscle of rats with insulin resistance induced by high-fat diet. METHODS: Twenty SD rats were randomly divided into normal control group with 10 rats and high-fat diet group with 10 rats. Rats in the two groups were fed with normal diet and high-fat diet for 12 weeks, respectively.RESULTS AND CONCLUSION: The insulin sensitive index was significantly decreased in the high-fat diet rats compared with the normal rats (P < 0.01). In obese rats, glucose tolerance and the acute first-phase insulin secretory response to glucose were impaired. The protein level of PTP-1B in the skeletal muscle of obese rats was significantly increased compared with the control group (P < 0.01). Insulin-stimulated IRS-2 phosphorylation in the skeletal muscle was reduced in the obese rats (P < 0.01). These indicate that the increased PTP-1B level and the reduced insulin-stimulated IRS-2 phosphorylations in the skeletal muscle seem to play an important role in the insulin resistance induced by high-fat diet.