| IntroductionWith the development of cardiac surgery using cardiopulmonary bypass, coronary artery bypass,PTCA and thrombolic technology so on,my-ocardial ischemia reperfusion injury is a crucial field to study. It was proved by many clinical and animal experiments that : lipid peroxidation caused by free radicals was one of the most important mechanisms of my-ocardial ischemia reperfusion injury . In the past, the level of MDA and SOD can represent the degree of myocardial ischemia reperfusion injury. However,they are flawed as stability is low and the detective results can be interferenced by many factors. Isoprostane is a newly discoveried metabolize product of arachidonic acid which is catalyzed by noncycloxygen-ase — dependent free radicals undergoing peroxidation. 8 — isoprostane has stable chemistry character and will increase significantly when oxida-tive injury happens. The study on detecting myocardial ischemia injury with the level of 8 — isoprostane has not been reported in china. We often apply intravenous anesthesia in cardiac surgery. Different intravenous anesthetics have different effects on myocardium. Propofol has protective function,while the effects of ketamine and gama —hydroxy butyrate are uncertain. The aim of this study was: 1 . to compare the effect of different doses of different intravenous anesthetics on lipid peroxidation caused by myocardial ischemia reperfusion injury of rats in vitro. 2. to observe the variety of 8 — isoprostane , MDA and SOD with the change of the concentration of the same anesthetic.Materials and methods1. grouping and drug administration60 Wistar rats (male and female) weighted 240 — 300g were selected for experiment and were divided into 10 groups at random,including control group ( C group ), propofol group ( P group ) and gama — hydroxy butyrate group ( R group ). The P^K and R groups had 3 subgroups of their own : PL:10 microM ,PM: 30 microM, PH: 100 microM;KL:5 mi-croM.KM: 10 microM, KH: 50 microM;RL: lmM, RM: 2. 5mM, RH: lOmM. We obtained the hearts of rats under aseptic condition and linked the Langendorff retrograde perfusion equipment. After being balanced 10 min with K—H fluid,every group was perfused with different perfusion fluids:the control group used K—H fluid continuously;PL group used K — H fluid containing 10 microM propofol;PM group used K—H fluid containing 30 microM propofol;PH group used K—H fluid containing 100 microM propofol;KL group used K—H fluid containing 5 microM ketamine;KM group used K—H fluid containing 10 microM ketamine;KH group used K — H fluid containing 50 microM ketamine;RL group used K—H fluid containing 1 mM y — OH;RM group used K—H fluid containing 2. 5 mMy—OH;RH group used K—H fluid containing 10 mM y—OH. The perfusion ceased 25 min after every group was perfused 10 min. Then they were reperfused 30 min with the same perfusion fluid that was used before the stop of perfusion. The myocardial tissues of left ventricle were obtained after perfusion,and then were preserved in —70°Crefrigeratory to detective 8 — isoprostane^MDA and SOD.2. Detective 8 — isoprostane with ELISA method3. Detective MDA with TBARS method.4. Detective SOD with xanthine oxidase method.5. Data analysisData are expressed as the mean± standard deviation(xzbs). Inter — group statistical testing was by one—way ANOVA . A level of p 0.05).2. Ketamine group(1) Compared with the control group, the low and medium dose group had no stastical difference in the level of 8 — isoprostane (P>0. 05). Compared with the control group,,the low and medium dose group, the high dose group increased the level of 8 — isoprostane(P0.05).(3) Compared with the control group,the groups of different doses had no stastical difference in the level of SOD(P>0. 05).3. Gama—hydroxy butyrate group(1) Compared with the control group, the low and medium dose group had no stastical difference in the level of 8 — isoprostane (P>0. 05) . Compared with the control group>the low and medium dose group,the high dose groupincreased the level of 8—isoprostane(P0.05).(3) Compared with the control group,the groups of different doses had no stastical difference in the level of SOD(PX). 05).Conclusions1. Different doses of propofol had the effect against lipid peroxidation. The PM group had the most significant function. Propofol may have the function of myocardial protection.2. Different doses of ketamine did not have the effect against lipid peroxidation. The KH group can promote lipid peroxidation and may have the effect of myocardial injury.3. Different doses of gama—hydroxy butyrate group did not have the effect against lipid peroxidation. The RH group can promote lipid peroxidation and may have the effect of myocardial injury.4. Compared with MDA and SOD, 8 —isoprostane is a more reliable and sensitive marker of lipid peroxidation.
|
PDF Full Text Request