Effect of captopril and isoflurane preconditioning on cell apoptosis during myocardial ischemia/reperfusion in rabbits / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of captopril and isoflurane preconditioning on cell apoptosis during myocardial ischemia/reperfusion (I/R) in rabbits.Methods Forty New Zealand white rabbits of both sexes,weighing 1.8-2.5 kg,were randomly divided into 5 groups (n =8 each) using a random number tablesham operation group (group S),group I/R,isoflurane preconditioning group (group I),captopril preconditioning group (group C) and captopril and isoflurane preconditioning group (group C + I).The animals were anesthetized with 3％ pentobarbital sodium 30 mg/kg.Myocardial ischemia was induced by occlusion of the left anterior descending branch of coronary artery for 30 min followed by 120 min of reperfusion.1.1％ isoflurane was inhaled for 30 min followed by 15 min washout before myocardial ischemia in group I.Captopril 25 mg/kg was given through a gastric tube into the stomach at 24 h before myocardial ischemia in group C.Captopril 25 mg/kg was given through a gastric tube into the stomach,24 h later 1.1％ isoflurane was inhaled for 30 min followed by 15 min washout,and then myocardial ischemia was performed in group C + I.The rabbits were sacrificed at the end of reperfusion and myocardial specimens were removed for microscopic examination and observation of ultrastructure,and for determination of the expression of Bcl-2 and Bax proteins (by Western blot).The apoptosis rate was detected by flow cytometry.Bcl-2/Bax ratio was calculated.Results Compared with group S,the apoptosis rate was significantly increased,the expression of Bcl-2 and Bax proteins was up-regulated,and Bel-2/Bax ratio was decreased in I/R,I,C and C + I groups (P ＜ 0.05).Compared with I/R,I and C groups,the apoptosis rate was significantly decreased,Bcl-2 protein expression was up-regulated,Bax protein expression was down-regulated,and Bcl-2/Bax ratio was increased (P ＜ 0.05),and the pathological changes were significantly attenuated in group C + I.Conclusion Regulation of Bcl-2/Bax ratio and inhibition of apoptosis in myocardial cells are involved in the mechanism by which isoflurane and captopril preconditioning reduces I/R injury in rabbits.