参麦注射液对糖尿病大鼠膈肌的保护作用

目的研究参麦注射液对糖尿病大鼠膈肌功能的保护作用,并探讨其机制.方法对链脲菌素诱导的糖尿病大鼠模型予以参麦注射液腹腔注射4周后,应用离体大鼠膈肌条,测定其单收缩张力(Pt)、最大强直张力(P0)、收缩时间(CT)和半舒张时间(RT1/2)、力-频率曲线、疲劳指数(FI)的变化;检测膈肌组织中的超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量的变化,并在电镜下观察超微结构的改变.结果与DM组相比,SMI组大鼠膈肌的Pt明显增加(P＜0.05),P0、FI显著增加(P＜0.01),CT、RT1/2明显缩短(P＜0.05);P1、P0、FI、CT与NC组比较均无显著性差异,RT1/2与NC组比较明显延长(P＜0.05);在给予10,20,40,60,100Hz刺激时,SMI组大鼠膈肌张力明显高于DM组(P＜0.05),但仍低于NC组;SMI组大鼠膈肌组织中SOD活力较DM组显著升高(P＜0.01),MDA含量较DM组显著减少(P＜0.01),两者较NC组均无显著性差异;电镜下,DM组大鼠膈肌肌纤维萎缩,Z线模糊不清,线粒体肿胀变性,部分有空泡变和髓样小体形成肌小节和线粒体形态改变,而SMI组膈肌肌纤维完整或仅有轻度萎缩,Z线较清晰,线粒体无肿胀变性或仅有轻度水肿.结论参注射对象糖尿病膈肌的损伤有保护作用.

Protective Effects of Shenmai Injection on Diaphragm of Diabetic Rats

Objective To study the effects of Shenmai Injection on funtion and structure of diaphragm of diabetic rats and to explore its mechanism.Methods Streptozotocin-induced diabetic rats were injected intraperitoneally with S henmai Injection for 4 weeks.After treatment,diaphragm contractility(Pt) was assessed by maximum tetanic tension(Po),time to peak contraction(CT),hal f relaxation time(RT1/2),force-frequency curve and fatigue index(FI) in in-vitro diaphragm strip;meanwhile SOD activity and MDA content in diaphragm we re detected and the changes of ultrastructure of rat diaphragm were observed.R esults Compared with model group,Pt increased remarkably(P<0.05),Po and FI increased significantly(P<0.01),and CT and RT1/2 were remarkably shorte ned in Shenmai group(P<0.05);Pt,P0,FI,and CT in Shenmai group did not di ffer from those in normal control group but RT1/2 was prolonged as compared with the normal control group(P<0.05).Under the stimulus frequency of 10,20, 40,60 and 100Hz,the diaphragm tension in Shenmai group was higher than that in the model group(P< 0.05) but lower than in the normal control group;MDA content in Shenmai group was lower(P< 0.01) and SOD activity was higher than tho se in the model group(P<0.01).The ultrastructure of diaphragm in the model group under electron microscope was shown as diaphragm fibres fractured,Z lines blurring,mitochondrions swollen and degenerated,but Shenmai Injection could prevent diaphragm cells from these ultrastructural damage.Conclusion Shenmai Injection can protect diaphragm of diabetic rats from damage.