Effects of hyperoside on the myocardical activities of ATPases and expressions of Cx43 and Kir2.1 in arrhythmia rats induced by ischemia-reperfusion / 中成药

ABSTRACT

AIM To investigate the effects of hyperoside,an anti-arrhythmic agent capable of reducing myocardial infarct size,on arrhythmic rats induced by ischemia-reperfusion (I/R) and the corresponding mechanism.METHODS Male SD rats were randomly assigned to sham operation group,model group and hyperoside group (50 mg/kg,n =15).The I/R model was reconstructed by the ligation of left anterior descending coronary artery for 30 min ischemia.Rats in the hyperoside group were injected with 50 mg/kg hyperoside intraperitoneally 10 min before ischemia.Heart rate,mean arterial pressure (MAP) and heart rate systolic blood pressure product (RPP) at time points of 10 min before ischemia (T0),30 min after ischemia (T1),30 min (T2),60 min (T3),120 min (T4) after reperfusion were recorded.ELISA method was used to determine serum CK-MB and cTnI,spectrophotometry to measure Na+-K+-ATPase and Ca2+-Mg2+-ATPase levels,HE staining to observe myocardial tissue changes,immunohistochemistry to investigate Cx43 protein,and Western blot to detect Kir2.1 protein expression.RESULTS At T1,T2,T3 and T4,the model group demonstrated significantly lower HR,MAP and RPP than those in the sham operation group (P ＜ 0.05),whereas the hyperoside group had higher HR,MAP and RPP than the model group.Both hyperoside group and the model group shared significantly higher arrhythmia score,levels of CK-MB and cTnI than the sham operation group (P ＜ 0.05) while their lower activities of Na +-K +-ATPase and Ca2+-Mg2+-ATPase,protein expressions of Cx43 and Kir2.1 than the sham operation group were noticed as well.But the hyperoside group displayed its lower arrhythmia score,levels of CK-MB and cTnI,and yet higher activities of Na +-K +-ATPase and Ca2 +-Mg2 +-ATPase,protein expressions of Cx43 and Kir2.1 than the model group (P ＜0.05).CONCLUSION Hyperoside in improving ventricular arrhythmia of I/R rats may contribute to the activity restoration of Na +-K +-ATPase and Ca2 +-Mg2 +-ATPase,and the up-regulation of Cx43 and Kir2.1 protein expressions.