Prevention For Acute Ischemic Heart Disease And Heart Failure Of Experimental Rabbits

The acute myocardial infarction (AMI) is an important type of coronary heart disease (CAD). The heart failure (HF) is a common complication of MI. The HF is an expression of the grave prognosis of MI. The prevention of HF is the basic link in the therapy of AMI. The mechanism on AMI causes HF is complex. After AMI, the situation of HF are very different which occur or not, quickly or slowly and mild or severe. The different developments are related with the position of coronary artery occlusion, the scope and speed of myocardium ischemia, damage and necrosis, the activated neuroendocrine system and the oxidative stress. But the concrete mechanism is still unclear. In the study, The left circumflex arteries of rabbits were ligated to obtain the animal models of acute ischemic heart disease. The animals of different groups were treated with different drugs or without drugs. After that, the related indexes of the experimental groups and the controlled groups were determined to study the function of oxygen free radical (OFR), as well as the safe and effect of drugs in ischemic heart disease (IHD) and HF. Objective:1. To obtain the animal models of acute ischemic heart disease by ligating the left circumflex arteries of rabbits.2. To compare the indexes of oxidative stress and myocardial function of the sham control group with those of the untreated post-Mi (PMI) group and study the relation of OFR and development of ischemic heart disease, heart failure.3. To study the effects of carvedilol on ischemic heart disease, heart failure and-5-oxidative stress.4. To evaluate the effect of captopril together with losartan and antisterone on ischemic heart disease ,heart failure by obstructing the activated-RAAS in different levels. Meterials and methods:21 rabbits were divided into 4 groups randomly: a sham control group(5), a untreated post-Mi (PMI) group(5). a carvedilol group(6) and a united drugs-treated group(5). The left circumflex arteries of rabbits were ligated without the sham control group to obtain the animal models of myocardial infarction. The animals of two drugs-treated groups were treated with carvedilol or captopril together with losartan and antisterone. After 60-70 days, we measured the following indexes: (1). The indexes of hemodynamic function of all animals: left ventricular end dilated pressure (LVEDP), left ventricular peak systolic pressure (LVPSP), mean aortic pressure (MAP) and atrial natriuretic peptide (ANP). (2).The indexes of oxidative stress of the sham control group, the untreated post-Mi (PMI) group and the carvedilol group: lipid peroxide malondialdehyde(MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-PX). (3). The activation of RAAS of the sham control group, the untreated post-Mi (PMI) group and the united drugs-treated group: angiotensin II (Ang II), aldosterone(ALD),and potassium in plasma. Results:1. The animal models of acute ischemic heart disease were obtained by thorax operation and ligating the left circumflex arteries of rabbits. We dyed the myocardium with nitro blue tetrazolium (NBT) to observe the blue or purple living myocardium, the white or yellow necrotic myocardium, the weak-6-ventricular wall and scars.2. The results by comparing the sham control group and the untreated post-Mi (PMI) group: MDA in plasma of the untreated PMI group increased and SOD, GSH-PX decreased, compared with the other group (p<0.05). The heart function of the untreated PMI group was inferior to that of the sham control group. LVEDP of the untreated PMI group were higher than the sham control group (p<0.05). LVPSP were lower in the untreated PMI group than the other group (p<0.05). The heart functions of the two groups are closely related with the situations of oxidative stress.3. The heart function of the carvedilol group was superior to that of the untreated PMI group. LVPSP of the carvedilol group was higher than the untreated PMI group (p<0.05). ANP of the carvedilol group was lower than that of the untreated PMI group (p<...