| The objective of this research is to study the effect of" shengmai injection " ,one kind of Chinese traditional medicine preparation, in alleviating myocardial ischemia and preventing the reperfusion injury. when it is applied as the additive of the perfusion liquid in the process of cardiac surgery with cardiopulmonary bypass (CPB).There are a lot of factors which can easily cause myocardial ischemia in the process of cardiac surgery with CPB,for example ,the composition of the perfusion liquid is different from normal blood , normal blood was diluted by various liquids and the blood cells contacting with foreign bodys, all of the above can cause blood composition 's physical and chemical property changes;The ventricle fibrillation can make ventricle wall tension increased high, which could easily result in the myocardial ischemia .The venous reflux interdicted during the CPB , aortic insufficiency , patent ductus arterious , pulmonary vein and the collateral circulation but not the coronary artery system is excessive, all of these factors can result in ventricle 's overload;whereas, when The ventricle is empty ,the coronary artery's flux was reduced by the cardiac muscles' contrasting, then ,the endocardium is ischemiaThrombus and air embolism which are produced during the CPB process, can obstruct the coronary artery; what damage the cardiac muscle most is the operation inside the heart ,when the aorta is clipping, how to protect the cardiac muscle during this process is the key to the heart function 's recovery the ischemia and anoxia of cardiac muscle cell result in the using up of ATP, without ATP ,the transportation of ions across the membrane can't be maintained, then a large quantity of Ca2+ comes together inside cells, making firm combination in a formation in proteinase in contraction, cause cardiac muscle convulsed.if the situation gets worse, Ca2 + and H+ will be stired up to releases the enzyme of lipoprotein sterone, the cell 's structure will be broken. the O2- free radical which were produced during the reperfusion further damage the cell's structur. when the cardiac muscle is ischemia, the oxidase process inside the mitochondrion,is terminated, the AMP 's phosphating to ADP and ATPs are inhibited, AMP accumulate inside the cardiac muscle cell , AMP then was decomposed to adenosine , inosine and hypoxanthines, all of them can spread from the cell's inside out, and will be swept when reperfusion which make ATP can not recovered to the normal level.ATP after using up of so can break the cell construction cardinal because of again the hour of perfusion releases the proptosis O2- free radical, it makes not saturated sterone in over oxidase but cause the cell breakage, the mechanism is an oxygen to be the ischemia period ATP after using up, cause the large quantity Ca2- aggregation, from but make tissue inside xanthine dehydrogenase change as the enzyme of xanthine oxidase, the latter make hypoxanthine with again perfusion hour hem inside plentifulness action creation O2- free radical, causing the cell breakage.Therefore the measure of protecting the cardiac muscle should fix attention on enhancing cardiac muscle's ATP and CP stores and supply, reducing the ATP depletion , preventing the Ca2 inside the cell accumulation , dissolving O2- free radical 's toxicity.considering the above damaging mechanism, currently, during the process of cardiac surgery , the concrete measure of the myocardial protection include, ⑴ , normal temperature, ventricle fibrillation, coronary artery continuous perfusion ,this method is mainly being used in coronary artery bypass grafting (CABG) , this method 's weakness:during the stage of ventricle fibrillation, the endocardium's blood flux still not enough, which cause phosphate stores descent, the lactic acid accumulates , cardiac muscle contractility descent.⑵ , whole body inside a hypothermia, interrupted clipping the aorta, the anoxia cardiac arrest, this method's weekness:each anoxia cardiac arrest need...
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