Correlation between myocardial ischemia-reperfusion-induced monophasic action potential amplitude change and myocardial damage

摘要

Objective:To study the correlation between myocardial ischemia-reperfusion-induced monophasic action potential amplitude (MAPA) change and myocardial damage.Methods:New Zealand rabbits were selected as experimental animals and randomly divided into control group and ischemia-reperfusion group (I/R group), myocardial ischemia-reperfusion injury models were established, then the heart was separated and the MAPA of myocardial intima layer, media layer and outer layer were determined in Langendorff perfusion system; serum samples and myocardial tissue were collected to determine the contents of myocardial injury molecules.Results: MAPA levels of myocardial intima layer, media layer and outer layer of I/R group were significantly lower than those of control group; CK-MB, cTnI, cTnT and MDA contents in serum as well as Bax, Caspase-3 and Caspase-9 mRNA expression in myocardial tissue of I/R group were significantly higher than those of control group and negatively correlated with MAPA levels of myocardial intima layer, media layer and outer layer while SOD, GSH-Px and HO-1 contents in serum as well as Bcl-2 and Bcl-xL mRNA expression in myocardial tissue were significantly lower than those of control group and positively correlated with MAPA levels of myocardial intima layer, media layer and outer layer.Conclusion:Myocardial ischemia - reperfusion can induce the decrease of MAPA and is closely related to myocardial oxidative stress injury and apoptosis.