The Study On Protective Effects Of Catalpol On Cardiomyopathy In Type 2 Diabetic Rats And Its Merchanisms

Objective:Through investigating the oxidative stress levels in myocardium of the rats with type 2 diabete mellitus,and further exploring the mechanism of action of catalpol on myocardial injury in type 2 diabetic rats,we provi-de experimental evidence for its clinical applications.Methods:Based on the method of random number table,8-week-old Wistar rats were randomly divided into normal group(10 rats)and experimental group(90 rats).Rats in the experimental group that were fed with high-fat and high-sugar diet for 8 weeks were injected intraperitoneally with STZ(15mg/kg),with fasting blood glucose≥16.7 mmol/L as a m-odel for type 2 diabetes.Then based on fasting blood glucose and body weight,the rats meeting the criteria of type 2 diabete mellitus were randomydivided into five groups,namely,the model group,the control group,the low or medium or high doses of the catalpol group,and there werel2 rats in each group.The normal group and the model group were filledwith distilled water(5ml/kg·d),the control group were trea-ted with metformin(90mg/kg·d),and Low,medium and high dose group were intragastric administration of Catalpol(2.5mg/kg·d,5mg/kg·d,10mg/kg·d).Then the general state of rats and Myocardial pathological changes were investigated,and the body weight,heart weight index,protein level related to myocardial oxidative stress,level of glucose and lipid metabolism,insulin resistance and heart function change were measured after 12 weeks of intervention in rats.Results:Compared with the blank group,the levels of body weight(BW),insulin sensitivity index(ISI),SOD activity of myocardium and E/A were decreased obviously(p<0.05 or p<0.01),the levels of heart weight index(HWI),fasting blood glucose(FBG),myocardial MDA content,fasting insulin(FI),NEFA content in serum and E/E’were significantly increased in the model group(p<0.05 or p<0.01).Compared with the model group,the levels of HWI,FBG,MDA,FI,NEFA and E/E’were significantly decreased(p<0.05 or p<0.01),the levels of BW,ISI,SOD and E/A were increased obviously(p<0.05 or p<0.01)in catalpol groups.Compared with the model group,the other indexes in addition to FBG,ISI and NEFA were significant difference(p<0.05 or p<0.01)in the high-dosage group.he levels of FBG,SOD and NEFA were increased(p<0.05),the other indexes were no significant difference(p>0.05)in the medium-dosage group.the other indexes in addition to FI and SOD were significant difference(p<0.05 or p<0.01)in the low-dosage group.Conclusion:1、The oxidative stress levels in myocardium of the rats with high-sugar and high-fat diet combined with STZ-induced type 2 diabetes were si-gnificantly increased,and it shows that the latter plays an importantrole inthe development of diabetic myocardiopathy.2、Catalpol can reduce myocardial tissue damage,increase SOD activity,reduce myocardial MDA content,significantly improve myocardial oxidative stress levels in type 2 diabetic rats,and it shows that in a certain dose range,Catalpol has a protective effect on myocardial injury in type 2 diabetic rats.3、Catalpol can improve the quality of life,reduce heart weight index,and regulate the disorder of glucose and lipid metabolism,improve ca-rdiac function and insulin resistance and so on in rats with type 2 diabete mellitus.Comprehensive efficacy is obvious.