| Ischemic heart disease(IHD)is one of serious diseases in mankind. The main cause of death in patients with cardiovasocular disease. Therefore, more and more studies on the mechanism and treatment have been focused.Administrating the myocardial ischemic drugs is still an important treatment measure of the treatment IHD at the present time.Anti-myocardial ischemic drugs balance myocardial oxygen supply and demand condition through dilating the coronary artery primarilyso as to, increase the coronary flow (CF), and further more together increase the oxygen supply, or decrease lower the myocardial oxygen consumption(MOC).The common used drugs include nitrates.Ca2+-antagonists and P-blockers to and so on. Although these durgs have obvious anti-myocardial ischemia effect, they show side effects, to some extend, such as tolerance phenomenon after long time nitrate treatment, negative inotropic effect taking Ca2+-antagonist and P-blockers, hypotension and arrhythmia. In recent years, many investigation indicated that IHD had obvious myocardial dysmetabolism, so some authors categorized IHM into metabolizable cardiomyopathies.In 1955, Friedman confirmed that acetylcamitine is producted from acetyl coenzyme and carnitine in liver. The same year, Fritz discovered that carnitine can facilitate fatty acid oxidation . It was proved that acetyl carnitine is the substrate of mitochondrion oxidative activation. The most characteristic theory is that carnitine performs an important function in long-chain fatty acid oxidative process in mitochondrion .Carnitine (L-CN) is a proper composition of various organize cells inside human body. In recent years, a series of clinical results about L- carnitine were reported, especially it's therapeutic function for cardiovascular disease, whichattracted the widespread interest. Effects of L-CN on cardiovascular system(CVS)include:0 Attenuate myocardial ischemia(MI)and myocardial remodling;(2) Reduce frequency of angina pectoris attack and the consumed dosage of Nitroglycerin,-(3) Improve the cardiac function; (4) Anti-arrhythmia.In 1982, it was found that there is relationship between endogenous carnitine and fatty acid metabolism and from that on, the effect of carnitine on energy metabolism of ischemia myocardium has been studied.(1) Free carnitine content in infarted region of patient with myocardial infarction(MI) was lower compared with patients with the other heart diseases;(2) Serious cardiac complication when acute myocardial infarction happened was related with the content of plasma FFA, which indicates that FFA accumulation has toxic effect on myocardium.In this study, by using different experiment methods, protective effects of L-Carnitine on myocardium and the possible mechanism of its protection function were studied. The results are following;1. The the rats myocardial ischemia(MI) models induced by Isoprenaline, L-CN has following effects:(l)Attenuate the damaging changes of ST segment after myocardial ischemia, reduce serum LDH, CK, GOT activity, lower content of lactic acid FFA and MDA in serum, SOD in cardiac tissue, increase the serum SOD activity, improve metaboilic level.(2)Decreae the area of myocardial necrosis and the degree of injury to myocardiacyte.(3) Reduce the change of myocardiolcyte ultra structure suffered from ischemia , obviously alleviate of mitochondrion swelling , the degree of structure injured and muscle fiber destroy.(4)Improve mitochondrion membrane fluidity in myocardium suffered from ischemia and hypoxia, exalt the stability of mitochondrion membrane .2.On the rats acute inyocardial infarction model induced by ligating left-anterior descending branch of coronary artery ,L-CN also has shown below effects:(1) Diminish the range of myocardial necrosis, release change ST segment myocardial ischemia (MI) injury .(2) Reduce the contents of serum ferment (CK, GOT, LDH) , lactic acid, MDA and FFA.(3)Increase the value of press in left ventricle , improve heart function . C...
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