银杏叶提取物对2型糖尿病大鼠膈肌收缩能力的影响

目的:观察银杏叶提取物(GbE)对2型糖尿病大鼠膈肌收缩能力和能量代谢酶活性的影响。方法:40只雄性SD大鼠按随机数字表法分为正常对照组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2型糖尿病大鼠模型。随机选取造模成功大鼠20只平均分成2组:糖尿病组、GbE治疗组。GbE治疗组按8mg/(kg.d)剂量腹腔注射GbE,持续8周。测定各组大鼠膈肌单收缩张力(Pt)、最大强直张力(P0)、疲劳指数(FI)的水平;检测膈肌组织中的细胞色素氧化酶(CCO)、乳酸脱氢酶(LDH)和琥珀酸脱氢酶(SDH)活性,并观察其超微结构的变化。结果:与对照组比较,糖尿病组大鼠膈肌Pt、P0、FI水平降低(P0.01);CCO、LDH、SDH活性下降(P0.01);电镜下主要表现为膈肌线粒体扩张,嵴变短,空泡化。GbE治疗组上述变化明显减轻。结论:GbE增强2型糖尿病大鼠膈肌有氧氧化和糖酵解能力,改善线粒体呼吸链功能,能提高2型糖尿病大鼠膈肌的收缩能力。

Effects of ginkgo biloba extraction on contraction capacity of diaphragm from type 2 diabetic rats

Objective：To investigate the effects of Ginkgo biloba extract （GbE） on the activities of energy metabolism enzymes and contraction capacity of diaphragm from type 2 diabetic rats.Methods：Forty SD male rats were randomly divided into normal control group （n=10） and model group （n=30）.Type 2 diabetes models were induced by feeding with high-sucrose-high-fat diet and intraperitoneal injecting 25mg/kg streptozotocin.20 successful models were rearranged to two groups：diabetic group and GbE treatment group,10 rats in each.Then the saline and 8mg/（kg·d）of GbE were respectively intraperitoneal injected,once a day continuously for 8 weeks.Then diaphragm contractility was assessed using Peak twitch tension（Pt）,Maximum tetanic tension （P0） and fatigue index（FI） in vitro diaphragm strip preparations.Cytochrome oxidase （CCO）,lactate dehydrogenase （LDH） and succinate dehydrogenase （SDH） in diaphragm were detected and the varieties of diaphragm ultrastructure were observed.Results：Compared with control group,Pt,P0 and FI in diabetic group decreased significantly （P0.01）;the activity of CCO,LDH and SDH in the tissues was more obviously reduced than those in control group （P0.01）.The ultrastructure in diabetic group under electron microscope indicated that diaphragm mitochondrions swelled and degenerated.The above changes were inhibited by GbE.Conclusion：GbE can enhance contraction capacity of diaphragm from type 2 diabetic rats by increasing the aerobic oxidation capacity,glycolytic capacity and the function of respiratory chain.