大豆异黄酮对胰岛素抵抗大鼠抵抗素基因表达的影响

目的探讨大豆异黄酮(SIF)改善高脂高蔗糖膳食诱导大鼠胰岛素抵抗(IR)状态的作用及可能机制。方法选用高脂高蔗糖饲料诱导的IR雄性SD大鼠,根据胰岛素抵抗指数(IRI)随机分为模型对照组和3个SIF组(50mg/kg·bw、150mg/kg·bw及450mg/kg·bw)。各组给予相应受试物1月后,酶法检测各组动物空腹血糖、放免法检测空腹血胰岛素、酶免法检测血抵抗素含量,实时定量RT-PCR法检测肾周脂肪组织抵抗素基因的mRNA水平。结果与模型对照组比较,450mg/kg·bwSIF组能明显降低大鼠肾周脂肪组织抵抗素基因mRNA的表达及血清抵抗素的含量。150mg/kg·bwSIF和450mg/kg·bwSIF组能显著降低空腹血胰岛素水平及IRI。3个SIF组的血糖与对照组比较差异无统计学意义。IRI与血清抵抗素水平存在着明显的正相关(r=0.355,P<0.05)。结论SIF可能具有通过下调抵抗素基因mRNA表达及降低血清含量而提高胰岛素敏感性的作用。

Effects of Soy Isoflavone on Gene Expression of Resistin in Insulin-resistance Rats

OBJECTIVE: To assess the effects of soy isoflavone (SIF) on improving insulin reistance (IR) status in IR rats induced by high-fat and high-sugar diet and explore the possible mechanisms. METHODS: IR rats were randomly divided into four groups according to their insulin resistance indices (IRI). The rats in one model control group and three SIF groups were fed via gavage with water solutions containing SIF at doses of 0 mg/ kg x bw, 50 mg/kg x bw, 150 mg/kg x bw, and 450 mg/kg x bw, respectively. After one month, fasting glucose, fasting insulin, resistin in serum, and resistin mRNA in adipocyte around kidney were detected by enzymologic method, radioimmunoassay, enzyme linked immunosorbent assay, and real time RT-PCR, respectively. RESULTS: Comparison between the model control group and the other groups revealed that serum resistin and resistin mRNA expression levels were lower in the 450 mg/kg x bw group, that insulin and IRI levels were lower in the 150 mg/ kg x bw group and 450 mg/kg x bw group, and that no differences in plasma glucose levels existed among the 4 groups. A positive correlation between IRI and serum resistin level (r = 0.355, P < 0.05) was observed. CONCLUSION: These results suggest that soy isoflavone may down-regulate resistin mRNA expression, decrease serum resistin level and enhance insulin sensitivity.