银杏叶提取物增强糖尿病大鼠模型膈肌摄取葡萄糖能力的作用研究

目的:观察银杏叶提取物(GbE)对糖尿病大鼠模型膈肌葡萄糖摄取率和葡萄糖转运体4(GLUT4)mRNA表达水平的影响.方法:40只雄性SD大鼠随机分为正常对照组10只,造模组30只.应用高糖高脂饮食加小剂量链脲佐菌素诱发糖尿病大鼠模型.随机选取造模成功大鼠20只均分成2组:糖尿病组、GbE治疗组.GbE治疗组按8 mg·kg~(-1)·d~(-1)剂量腹腔注射GbE,持续8周.检测各组大鼠空腹血糖和胰岛素水平,膈肌组织葡萄糖摄取率和CLUT4 mRNA水平,并观察其超微结构的变化.结果:与正常对照组比较,糖尿病组大鼠空腹血糖和胰岛素升高(P<0.01);膈肌葡萄糖摄取率和GLUT4 mR-NA水平下降(P<0.05,P<0.01);电镜下主要表现为膈肌线粒体扩张,嵴变短,空泡化.GbE治疗组L述变化明显减轻.结论:GbE可部分纠正糖尿病大鼠模型高血糖、高胰岛素状态,并减轻膈肌损伤,其作用与增强膈肌GLUT4基因表达,促进膈肌对葡萄糖的摄取和利用有关.

Effect of Ginkgo biloba extract on glucose uptakeof diaphragm in diabetic rats

Objective: To investigate the effects of Ginkgo biloba extract (GbE) on the glucose uptake rate and gene expression of glucose transporter 4 (GLUT4) in diaphragm of diabetic rats. Method: Forty SD male rats were randomly divided into normal control group (n=10) and model group (n=30). Diabetic models were induced by feeding with high-sucrose-high-fat diet and intraperitoneal injecting 25 mg·kg^-1 streptozotocin. 20 successful models were rearranged to two groups: diabetic group and GbE treatment group, 10 rats in each. Then the saline and 8 mg·kg^-1·d^-1 of GbE were respectively intraperitoneal injected, once a day continuously for 8 weeks. The contents of fasting blood glucose (FBG), fasting insulin (FINS) were detected, respectively. The glucose uptake rate and gene expression of GLUT4 in diaphragm were determinated and the varieties of diaphragm ultrastructure were observed. Result: Compared with control group, levels of FBG and FINS obviously increased in diabetic rats(P<0.01), but the glucose uptake rate and expression of GLUT4 mRNA in diaphragm decreased significantly (P<0.05, P<0.01). The ultrastructure in diabetic group under electron microscope indicated that diaphragm mitochondrion swelled and degenerated. The above changes were inhibited by GbE. Conclusion: GbE can improve the glucose metabolism in diabetic rats and reduce the diabetes-induced diaphragm damage. The action mechanism of the drug may be related to promote the mRNA expression of GLUT4 in diaphragm and improve the uptake and metabolism of blood glucose.