大豆异黄酮对胰岛素抵抗大鼠胰岛素敏感性及瘦素基因表达的影响

目的:观察大豆异黄酮(SIF)对高脂膳食诱导的胰岛素抵抗(IR)大鼠血清瘦素水平及白色脂肪组织瘦素mRNA表达的影响,并探讨SIF提高胰岛素敏感性的可能机制.方法:选用高脂饲料诱导的IR雄性SD大鼠,根据其胰岛素抵抗指数(IRI)随机分为模型对照组(水)和3个SIF组(50 mg/kg,150 mg/kg及450 mg/kg).各组经口灌胃给予相应受试物1个月,空腹过夜后取材,用酶法检测各组动物空腹血糖、用放射免疫法检测空腹血胰岛素、用酶联免疫法检测血清瘦素含量,以实时定量RT-PCR法检测肾周脂肪组织瘦素基因的mRNA水平.结果:与模型对照组比较,SIF 150 mg/kg和450 mg/kg组能显著降低空腹血胰岛素水平及IRI,SIF450 mg/kg组能明显降低大鼠体重及肾周脂肪组织瘦素基因mRNA的表达、提高血清瘦素的含量.结论:SIF可能具有改善瘦素抵抗的作用,并进而提高胰岛素的敏感性.

Effect of soy isoflavone on gene expression of leptin and insulin sensibitity in insulin-resistant rats

Objective:To explore the effects of soy isoflavone ( SIF) on gene expression of leptin and insulin sensibility in insulin-resistant (IR) rats induced by high-fat, and to reveal the mechanisms of SIF in ameliorating insulin sensibility. Methods:IR rats were randomly divided into four groups based on their insulin-resistant indexes (IRI): one model control group and three SIF groups that were gavaged with water solutions with SIF at doses of 0 mg/kg,50 mg/kg,150 mg/kg,and 450 mg/kg,respectively. After one month, fasting glucose , fasting insulin, leptin in serum, and leptin mRNA in the perirenal adipo-cyte were detected by enzymic method, radioimmunoassay, enzyme linked immunosorbent assay, and real time quantitative RT-PCR, respectively. Results:The model control group was used to compare against the other groups:(1) Insulin and IRI were lower in the 150 mg/kg and 450 mg/kg groups; (2) In the 450 mg/kg group, body weight and leptin mRNA expression were lower, serum leptin content was higher. Conclusion:These results indicate that soy isoflavone might decrease body weight of rats and leptin mRNA,increase serum leptin level,and ameliorate leptin and insulin sensitivities.