胰岛素抵抗大鼠骨骼肌中蛋白激酶B表达及葡萄糖转运蛋白4转位的改变

目的研究高脂饮食喂养的胰岛素抵抗(IR)大鼠骨骼肌中蛋白激酶B(PKB)表达和葡萄糖转运蛋白4(GluT4)转位的改变及饮食治疗、葛根素、罗格列酮干预的影响。方法将雄性SD大鼠50只随机分为正常饮食(A)组和高脂饮食(B)组,2个月后再将B组大鼠随机分为高脂饮食(C)组、正常饮食干预(D)组、葛根素干预(E)组和罗格列酮干预(F)组。干预1个月后检测骨骼肌中PKB的表达及转位至质膜的GluT4含量。结果C组大鼠产生了明显的IR,骨骼肌中PKB的表达较A组显著降低(P<0.01),转位到质膜上的GluT4含量显著减低(P<0.01);D、E、F组大鼠IR明显改善,骨骼肌中PKB的表达较C组大鼠显著增加(P<0.01),GluT4含量较C组大鼠显著升高(P<0.01)。结论高脂饮食喂养的SD大鼠骨骼肌产生明显的IR,骨骼肌中Ins诱导的PKB表达降低,Ins刺激的GluT4向质膜的转位减少。饮食治疗及葛根素、罗格列酮干预能增加骨骼肌中Ins刺激的PKB表达及GluT4向质膜的转位。

Changes in protein kinase B (PKB) expression and glucose transporter 4 (GluT-4) translocation in skeletal muscle of insulin resistant rats

Objective To study the changes in PKB expression and GluT-4 translocation in skeletal muscle of insulin resistant rats fed with high fat diet and the effect of intervention treatments. Methods Normal male SD rats were divided into two groups taking either normal diet(A,n=9) or high-fat diet(B,n=41). After two months, rats in group B were randomly divided into four groups: high-fat diet group(C,n=9), normal diet plus intervention group(D,n=9), kakonein intervention group(E,n=11) and rosiglitazone intervention group(F,n=12). After another one month intervention treatment, their PKB expression and GluT-4 translocation of skeletal muscle were tested. Results Group C developed obvious insulin resistance(IR), and their PKB expression and insulin-stimulated translocation of GluT-4 to plasma membrane in skeletal muscle decreased significantly compared with normal control (group A)(P<0.01). Compared with group C, the PKB expression and insulin-stimulated translocation of GluT-4 to plasma membrane increased obviously in group D,E,F (all P<0.01). Conclusions High-fat fed SD rats can develop obvious IR. Their insulin-stimulated PKB expression and translocation of GluT-4 to plasma membrane in skeletal muscle decrease obviously. Intervention with diet, kakonein or rosiglitazone can increase PKB expression and insulin-stimulated translocation of GluT-4 to plasma membrane in skeletal muscle.