瘦素在胰岛素抵抗大鼠脂肪组织中的表达及意义

摘要

Objective To evaluate the expression of leptin in rat fat tissue with insulin resistance ( IR) induced by high-fat diet.Methods Rat model with IR induced by high-fat diet was confirmed by euglycemic clamp.Insulin and free fatty acid ( FFA) were measured by chemiluminescent immunoassay and biochemistic chromatometry method.Expression of leptin in fat tissue was identified by real-time PCR and Western blot analysis, respectively.Results After 4 weeks highfat diet, the glucose infusion rate of IR rats was higher than that in the control group (P＜0.05).Compared with the control group , the levels of FFA , body weight, serum glucose and insulin in IR rats increased significantly (P＜ 0.05 ) .The expression of leptin mRNA and protein increased ahout 68％ and 200％ , respectively.Conclusions High-fat diet can induce IR state in Wistar rat, up-regulate gene transcription and translation of leptin in fat tissue.Leptin mayhe play a role in lipid-pancreatic island metabolism.%目的 研究高脂肪膳食诱导的胰岛素抵抗(IR)大鼠脂肪组织中瘦素的变化规律及意义.方法 IR大鼠模型采用高脂肪膳食诱导并经钳央技术证实.采用微型血糖仪、化学发光免疫分析法和生化比色法测定全血葡萄糖、血清胰岛素和血清游离脂肪酸(FFA)的变化.应用实时定量PCR和Western印迹杂交分析检测脂肪组织中瘦素的mRNA和蛋白质在IR状态下的表达情况.结果 高脂肪膳食喂养4周后,实验组大鼠葡萄糖输注率较对照组降低,FFA、体质量、全血葡萄糖、血清胰岛素水平均高于对照组;高脂肪膳食诱导的IR大鼠脂肪组织中瘦素mRNA和蛋白质的表达均较对照组增加(P＜0.05).结论 高脂肪膳食可诱导大鼠产生IR,并增强脂肪组织中瘦素基因的转录和翻译.瘦素可能是参与调节脂肪-胰岛轴的主要因素之一.