丹蛭降糖胶囊改善肥胖大鼠骨骼肌胰岛素抵抗机制的初步研究

A Pilot Study on Mechanisms of Danzhi Jiangtang Capsule in Improvement of Skeletal Insulin Resistance in Obese Rats

摘要:

目的: 探讨丹蛭降糖胶囊对高脂饮食诱导的肥胖大鼠骨骼肌脂联素(APN),脂联素受体结合蛋白(APPL1)及葡萄糖转运蛋白4(GLUT4)表达的影响.方法: 雄性SD大鼠随机分为普通饮食组(NC组)、单纯高脂饮食组(HF组)、高脂饮食+丹蛭降糖胶囊组(FD组,470 mg ·kg^-1 ·d^-1)、高脂饮食+吡格列酮组(PIO组,10 mg ·kg^-1 ·d^-1)、高脂饮食+丹蛭降糖胶囊联合吡格列酮组(FD/PIO组,丹蛭降糖胶囊470 mg ·kg^-1 ·d^-1+吡格列酮10 mg ·kg^-1 ·d^-1),ig给药4周.NC组继续普通饲料喂养,给予蒸馏水ig.应用全自动生化分析仪测定骨骼肌甘油三酯(TG)含量;免疫组化及Western blot检测APN,APPL1,GLUT4在骨骼肌组织中的定位以及蛋白表达.结果: ①HF组骨骼肌内TG含量显著高于NC组(P<0.01).相较于HF组,各干预组大鼠骨骼肌TG含量均明显下降(P<0.05).②免疫组化以及Western blot检测结果显示,HF组APN,APPL1,GLUT4表达较NC组明显降低(P<0.05);各干预组APN,APPL1,GLUT4表达均较HF组明显增加(P<0.05).③相关分析发现,大鼠骨骼肌TG含量与HOMA-IR呈正相关(r=0.63,P<0.01),与APN,APPL1,GLUT4蛋白均呈负相关(r分别为-0.57,-0.51,-0.62,均P<0.01);HOMA-IR与APN,APPL1,GLUT4蛋白均呈负相关(r分别为-0.49,-0.44,-0.52,均P<0.05,P<0.01).结论: 丹蛭降糖胶囊可减轻骨骼肌脂质沉积,上调骨骼肌组织中的APN,APPL1,GLUT4表达,从而改善骨骼肌胰岛素抵抗.

Abstract:

Objective:To investigate the effect of Danzhi Jiangtang capsule on protein expression of adiponectin (APN), adaptor protein containing PH domain, PTB domain and leucine zipper motif1 (APPL1) and glucose transporter 4 (GLUT4) in skeletal muscle in obese rats fed with high-fat diet. Method: Male Sprague-Dawley rats were randomly divided into basal diet group (NC group), untreated high-fat diet group (HF group), high-fat diet plus Danzhi Jiangtang capsule (FD group, 470 mg · kg^-1 · d^-1), high-fat diet plus pioglitazone (PIO group, 10 mg · kg^-1 · d^-1), high-fat diet plus Danzhi Jiangtang capsule and pioglitazone (FD/PIO group, 470 mg · kg^-1 · d^-1 for Danzhi Jiangtang capsule plus 10 mg · kg^-1 · d^-1 for pioglitazone). These treatment drugs were added to the animals by intragastric administration for 4 weeks. The animals in NC group continued to be given the basal diet and distilled water by intragastric administration. The contents of triglyceride in skeletal muscle were measured by automatic biochemical analyzer, and protein expression of APN, APPL1 and GLUT4 were determined by immunohistochemistry and Western blot analysis, respectively. Result: ①The contents of triglyceride in skeletal muscle were significantly higher in HF group than in NC group (P<0.01). Compared with HF group, The contents of triglyceride in skeletal muscle in each intervention group were reduced significantly (P<0.05).②Immunohistochemistry and Western blot analysis revealed that protein expression of APN, APPL1 and GLUT4 in skeletal muscle in HF group were signicantly lower than in NC group (P<0.05). Compared with HF group, The APN, APPL1 and GLUT4 expression in skeletal muscle in each intervention group were increased significantly(P<0.05).③Pearson correlation analysis showed that the contents of triglyceride in skeletal muscle were positive correlated with HOMA-IR (r=0.63, P<0.01). By contrast, the contents of triglyceride in skeletal muscle were negative correlated with protein expression of APN, APPL1 and GLUT4 (r=-0.57, -0.51, -0.62, respectively, all P<0.01). In addition, HOMA-IR was negative correlated with protein expression of APN, APPL1 and GLUT4 (r=-0.57, -0.51, -0.62, respectively, all P<0.05, P<0.01). Conclusion: Danzhi Jiangtang capsule can upregulate the expression of APN, APPL1 and GLUT4 in skeletal muscle of obese rats, reduce lipid deposition in skeletal muscle, thus improve skeletal insulin resistance.