Effect of dexmedetomidine on monophasic action potential amplitude in myocardial ischemia-reperfusion and its correlation with myocardial injury

摘要

cqvip:Objective: To study the effect of dexmedetomidine on monophasic action potential amplitude (MAPA) in myocardial ischemia-reperfusion and its correlation with myocardial injury. Methods: SD rats were selected as the experimental animals and randomly divided into control group, ischemia reperfusion group (I/R group) and dexmedetomidine group (Dex group);I/R group and Dex group were made into myocardial ischemia-reperfusion injury models, and Dex group were given exmedetomidine intervention;the MAPA of myocardial tunica intima layer, tunica media layer and tunica externa layer were measured in Langendorff perfusion system;myocardial tissue was collected to determine the contents of oxidative stress molecules and the expression of apoptosis genes. Results: The MAPA levels of myocardial tunica intima layer, tunica media layer and tunica externa layer as well as Klotho and SOD contents in myocardial tissue of I/R group were significantly lower than those of control group whereas CaMKII, NOX2, NOX4 and MDA contents as well as CaSR, USP14, JNK, Bax, Fas and Caspase-3 mRNA expression in myocardial tissue were significantly higher than those of control group;the MAPA levels of myocardial tunica intima layer, tunica media layer and tunica externa layer as well as Klotho and SOD contents in myocardial tissue of Dex group were significantly higher than those of I/R group whereas CaMKII, NOX2, NOX4 and MDA contents as well as CaSR, USP14, JNK, Bax, Fas and Caspase-3 mRNA expression in myocardial tissue were significantly lower than those of I/R group;Pearson test showed that the MAPA levels of myocardial tunica intima layer, tunica media layer and tunica externa layer were negatively correlated with CaMKII, NOX2, NOX4 and MDA contents as well as CaSR, USP14, JNK, Bax, Fas and Caspase-3 mRNA expression in myocardial tissue, and positively correlated with Klotho and SOD contents. Conclusion: Dexmedetomidine can increase the MAPA in myocardial ischemia-reperfusion process, and is closely related to the inhibition of oxidative stress response and apoptosis.