| Recent study indicated that propofol has evident cardioprotective effect after ischemica and reperfusion injury, while this benefit of mechanism is really unclear. This cardicoprotective effect may contribute to its antioxidant activity and inhibiting the lipid peroxidation, decreasing consumption of ATP in the myocardium and blocking the L-type Ca2+ channel in the ventricular myocardium, as reported. The mechanism of myocardium ischemia reperfusion injury involve in generating of reactive oxygen species, overload of Ca2+ and releasing of catecholamine by ischemia. Myocardium ischemia is a radical stress, which can cause adrenergic sympathetic overexcitation and overrelease catecholamine. Overreleasing of catecholamine can injury heart, and its mechanism may be (1) myocardium fibre abruption and broken for heart over contraction (2) increase oxygen consumption of heart (3) interruption engery metabolism of heart and reduce production of ATP. (4) enhance adhesion and release of platelet and affect coronery system, intensify myocardium ischemia. (5) augmentation reactive oxygen species by selfoxidate of catecholamine, enhance myocardium injury. Propofol is an intravenous anesthetic with a rapid onset and offset of anesthesia. Its undesirable hemodynamic effects and negative inotropic effect are associated with restraining release of catecholamine. In this work, we compared of two kind of isolated rat perfusion preparations (Langendorff and Working Heart), set up Working Heart preparations,and studied cardicoprotective of propofol on postischemia-reperfused left ventricular function, myocardia metabolize and arrhythmia. Concentration of catecholamine, CK and the changes in ultrastructure of heart cells was examed to manifest the mechanism of cardicoprotective effect of propofol. The main work was described as follows:1. Comparison of Two kind of Isolated Rat Perfusion Preparations: Our study observed the changes of left ventricular function before and after global ischemia-reperfusion in two kinds of isolated rat heart of Langendorff and Working Heart preparation, and provided an optionable way for our research. The results showed that CF and HR in Langendorff preparation were not significantly different compared to Working Heart preparation(P>0.05), but LVPSP,LVEDP,LVDP×HR decreased significantly(P<0.01) before ischemia. So, left ventricular function in Langendorff preparation is very less, AF and CO can't be detected. The study that CO and other hemodynamic value need be observed is benefit adopting Working Heart preparation. During reperfusion, CF recovered to 91.3% and 56.7% of their preischemia control value in Langendorff and Working Heart preparation respectively, and HR,LVPSP,LVEDP,LVDP×HR recovered significantly better in Langendorff preparation than in Working Heart preparation(P<0.05). Showed from results, we can see that Working Heart preparation is more like integral preparation than Langendorff preparation.2. Restraining effect of propofol to release of catecholamine during ischemia and reperfusion in isolated Working rat Hearts To investigate the protective mechanism of propofol on postischemia-reperfused left ventricular function and myocardia metabolize in isolated working rat heart preparation by examining concentration of catecholamine in flow of coronary artery. It can be observed from results that propofol have evident cardicoprotective effect and restrain release of catecholamine during ischemia and reperfusion in isolated working rat hearts. It was described as follow (1) Group 50μmol and 100μmol recovered significantly better than control group, and group 50μmol recovered best in all groups. (2) CK from coronary flow in all of group propofol was significantly decreased than group control. (3) Propofol significantly restrained overrelease of catecholamine (especially noradrenaline) by ischemia, and seriousness when high concentration. Concentration of noradrenaline from coronary flow in group 50μmol was 94.5±8.2pg/ml and in group 100μmol was 21.3±9.8pg/ml,more d...
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