瘦素在胰岛素抵抗大鼠脂肪组织中的表达及意义

Expression of leptin in rat fat tissue with insulin resistance

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夹技术证实。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。

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 high-fat diet,the glucose infusion rate of IR rats was higher than that in the control group（P0.05）.Compared with the control group,the levels of FFA,body weight,serum glucose and insulin in IR rats increased significantly（P0.05）.The expression of leptin mRNA and protein increased about 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 maybe play a role in lipid-pancreatic island metabolism.