内脂素基因过表达对胰岛素抵抗大鼠胰岛素敏感性的影响

目的 探讨内脂素基因过表达对高脂诱导胰岛素抵抗(IR)大鼠胰岛素敏感性的影响.方法 构建大鼠内脂素基因真核表达质粒,并用该质粒转染高脂喂养诱导的IR大鼠模型.在转染前后采用两次高胰岛素-正糖钳夹技术评价大鼠胰岛素敏感性的变化.结果 成功构建了内脂素真核表达载体pcDNA3.1内脂素.实验组大鼠在pcDNA3.1内脂素质粒注射后3 d血浆内脂素水平较注射前明显升高(2.19 ±0.36 vs 0.98±0.27,P＜0.01);在两次胰岛素钳夹中,pcDNA3.1内脂素质粒注射后葡萄糖输注率较注射前明显升高(32.6 ±1.2)mg·kg-1·min-1 vs(24.0±1.2)mg·kg-1·min-1,P＜0.01];总胆固醇、高密度脂蛋白胆固醇则较质粒注射前明显降低(2.36±0.22)mmol/Lvs(1.60±0.21)mmol/L和(1.41±0.24)mmol/L vs(0.88±0.11)mmol/L,均P＜0.05];在转染前后基础血糖和胰岛素水平无明显变化.结论 内脂素质粒转染使IR大鼠血浆内脂素水平升高,胰岛素敏感性增强.

Effects of visfatin gene overexpression on insulin sensitivity in the insulin-resistant rats indueed by high-fat diet

Objective To investigate the effects of visfatin gene overexpression on insulin sensitivitv in insulin-resistant(IR)rats induced by high-fat diet.Methods The recombinant visfatin Dlasmid was constructed and transfected into IR rats induced by high-fat diet.The euglycemic hyperinsulinemic clamp experiments were performed for evaluation the change of insulin sensitivity before and after administration.Results The expression plasmid of visfatin were successfully constructed.After 3 days for plasmid injecting,plasma visfatin levels and glucose infusion rates were significantly increased(2.19±0.36 vs 0.98±0.27 and 32.6±1.2 vs 24.0±1.2 mg·kg-1·min-1,respectively,all P＜0.01),and total cholesterol and high-density lipoprotein cholesterol(HDL-C)were significantly decreased(2.36±0.22 vs 1.60±0.21 mmol/L and 1.41±0.24 vs 0.88±0.11 mmol/L,respectively,all P＜0.05)in high-fat diet rats.Conclusion The transfection of visfatin plasmid enhanced plasma visfatin level and improved insulin sensitivity in IR rats induced by high-fat diet.