高脂或高糖饮食诱导胰岛素抵抗大鼠的附睾脂肪组织视黄醇结合蛋白4表达

目的观察不同膳食结构,即高脂或高糖饮食对大鼠附睾脂肪组织视黄醇结合蛋白4(RBP4)表达的影响。方法雄性SD大鼠随机分为3组,普通饮食组予普通饲料,高脂饮食组予高脂饲料,高糖饮食组予高糖饲料。喂养8周后,行口服糖耐量试验检测胰岛功能,取空腹血清测血糖、血脂和胰岛素水平等,并取附睾和肾周脂肪组织,称重,计算脂体比,免疫组织化学定量检测附睾脂肪组织RBP4表达水平,反转录-聚合酶链反应检测附睾脂肪组织RBP4和葡萄糖转运子4(GluT4)mRNA表达水平。结果8周后,高脂和高糖饮食组大鼠空腹胰岛素水平和胰岛素抵抗均显著高于普通饮食组(P值均＜0．01)。高脂和高糖饮食组大鼠0、30、60及120min血糖、胰岛素水平均显著高于普通饮食组(P值分别＜0．05、0．01),胰岛素曲线下面积(AUC_(INS))均显著高于普通饮食组(P值均＜0．01)。与普通饮食组相比,高脂和高糖饮食组大鼠糖耐量减退、空腹血糖和胰岛素升高、脂体比增加(P值分别＜0．05、0．01)。高脂和高糖饮食组大鼠三酰甘油水平显著高于普通饮食组(P值均＜0．01),两组附睾脂肪组织RBP4 mRNA水平分别是普通饮食组的2．35倍和2．47倍(P值均＜0．05),而GluT4则为普通饮食组的73．1%和66．7%(P值均＜0．05)。结论高脂和高糖饮食均能引起内脏脂肪组织RBP4表达增加, RBP4可能与腹内型肥胖相关。

High fat or high carbohydrate diet induces an increase in retinol-bindjng protein 4 expression in epididymal fat tissue of rats

Objective To observe the effects of high carbohydrate and high fat diet on the expression of reti- nol binding protein 4(RBP4)in rat epididymal fat tissue.Methods Male SD rats were divided into 3 groups and were fed with chow,high-fat,and high-carbohydrate diets,respectively.After 8 weeks,oral glucose tolerance test was performed and plasma fasting glucose,lipid profile,and insulin were measured.Epididymal and kidney peripheral fat tissues were weighed and fat-body ratio was calculated.RBP4(protein and mRNA)and GluT4(mRNA) levels were determined by immunohistochemistry and/or by RT-PCR.Results The rats fed with high-fat and high-carbohydrate diets had impaired glucose tolerance,higher fasting glucose,and fasting insulin levels,larger body-fat ratio,and higher triglyceride levels than those fed chow diet.RBP4 mRNA expression levels in epididymal fat tissues in rat with high-fat and high-carbohydrate diets were 2.35 and 2.47 times higher than those with the chow diet,respectively;whereas GluT4 mRNA expression levels were 1.37 and 1.50 times lower.Conclusion High-fat and high-carbohydrate diets induce RBP4 over expression in fat tissues,and RBP4 might be associated with visceral obesity.