| Objective: The cause of acute myocardial infarction (AMI) is that sudden obstruction of one of the coronary arteries cut off all the flow of blood to the area of the heart muscle beyond the obstruction and the myocardial cells deprived of their normal blood supply will die. It usually resulted in the severe, prolonged, and intense pain of a heart attack. AMI is one of the severe and emergency cases in internal medicine. According to the World Health Organization (WHO), the morbility is gradually increasing year by year with average 4.32%, and it has become our number-one killer disease recently. This study is to investigate changes of the level of creatine phosphokinase (CPK), free fatty acid (FFA), free radical metabolism in serum of rats with AMI without early successful reperfusion, then measure their cardial hypertrophy index, collagen contents of myocardial, and observe the myocardial patho-structure under light microscope and electron microscope, in order to evaluate effect of trimetazidine and herbal compound kuanxin on myocardial protection and restrain ventricle reconstitution after AMI and to explore the probable mechanism.Methods: Forty male healthful SD rats were divided into five groups randomly. each group included eight rats, namely: sham operation control group (group C), AMI model group (group M), TMZ group (group T), herbal compound kuanxin group (group K), and two drugs allied treatment group (group A).The rats were fed daily with ordinary food .Each rat in drug interved groups was additionally fed with corresponding drug in addition.One week later, Models of ligation of the anterior descending branch of left coronary artery were established. Electrocardiogram was recorded before and after ischemia respectively, and ST segment elevation and the cardiac apex became dark red mean success in establishment of model. In the group C ,the heart was exposed after the chest had been opened, but not ligated. Then collected serum for measuring activities of CPK, T-SOD and MDA in each group 24 hours after AMI. All rats were keep on fed for four weeks after the operation. At the end of the experiment, all rats were killed. Heart tissue were collected for being measured myocardial hypertrophy index and collagen contents of myocardial. Heart tissue were collected for being observing under light microscope and electron microscope in each group.Results: 1. Twenty-four hours after operation, serum activities of CPK and concentration of MDA in model established groups were significantly increased than those in group C (all P<0.01), while serum activities of T-SOD were significantly decreased than those in group C (all P<0.01). This three indexes in group M has the most significantly change of all (all P<0.001),and also had significant difference compared with group T, K, A (all P<0.001). But there was no difference between group T and group K (all P>0.05). Compared with group T and group K, serum CPK and MDA were lower, T-SOD were higher with significant difference(all P<0.05). 2. Serum concentration of FFA in model established groups were significantly increased than those in group C (all P<0.01).Serum concentration of FFA in group T (115.66±34.74 umol/l) and group A(135.67±20.12 umol/l)were significantly lower than those in group M (all P<0.05), but Serum concentration of FFA in group K (198.72±12.11 umol/l) were not significantly diferent from those in group M(P=0.12). 3. Four weeks after operation, the level of myocardial hydroxyproline , that is the content of myocardial collagen in all model established groups were significantly increased than those in group C (all P<0.05), and myocardial hypertrophy indexes were all significantly increased than those in group C (all P<0.001) as well. Compared with group M the two indexes in all drug intervene groups were significantly decreased (all P<0.01), especially in group A (P<0.001). Furthermore there was correlation between the content of myocardial collagen and activities of serum CK(r=0.9243, P<0.001), activities of serum T-SOD (r=-0.8306,p<0.001) and concentration of serum MDA (r=0.9475,p<0.001). 4. The outcome from the light microscope and electronic microscope indicate group C is nearly normal while there were obvious damages in group M.The damanges in group T, K and A are much more slighter than that of group M. Observed under light microscope by MASSON dyeing, there were less myocardial collagen fibers in drug intervene groups than those in group M, especially in group A.Conclusions: 1. The way of establish the model of AMI in rats by ligating the anterior descending branch of left coronary artery was proved indeed effective. 2. Trimetazidine and herbal compound kuanxin can reduce the releasing of CK, relieve myocardiolysis. 3. Oxygen free radicals take part in myocardial acute ischemia injury during AMI. Trimetazidine and herbal compound kuanxin can scavenge oxygen free radicals, so that thay have cardioprotective action, and two drug affiliation has better effect. 4. Trimetazidine can optimize myocardial metabolism,so that produce a marked effect on myocardial protection. And herbal compound kuanxin has not the analogic effect. 5. Trimetazidine and herbal compound kuanxin can improve the structure in cardiac muscular tissues and micro-structure of cadiocyte and plastiosome. 6. Trimetazidine and herbal compound kuanxin can cut down the myocardial hypertrophy indexes and reduce collagen fibers accumulation, so that restrain ventricle remodeling, relieve myocardial fibrosis, and elevate the complaisance of AMI cardiac muscle. This always improve the systole and diastolic function of heart and probablely result in more better prognosis. Two drug affiliation has better effect. |
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