Effects of sevoflurane postconditioning on cardiomyocyte apoptosis during myocardial ischemia-reperfusion in rats

Objective To investigate the effects of sevoflurane postconditioning on cardiomyocyte apoptosis during myocardial ischemia-repeffusion (I/R) in rats.Methods Forty-five healthy male Wistar rats weighing 250-280 g were randomly divided into 3 groups ( n =15 each):group sham operation ( group S) ; group I/R and group sevoflurane postconditioning (group Spo).The animals were anesthetized with intraperitoneal 3％ pentobarbital 45 mg/kg,tracheally intubated and mechanically ventilated.Myocardial I/R was produced by occlusion of anterior descending branch of left coronary artery for 30 min followed by 120 min reperfusion in groups I/R and Spo.In group Spo the animals inhaled 2.5％ sevoflurane for 5 min starting from 1 min before reperfusion was started.The animals were sacrificed at the end of 120 min reperfusion.Their hearts were removed for measurement of infarct size and the area at risk and determination of apoptotic index (the number of apoptotic cells/the total number of cells) and Bcl-2 and Bax protein and mRNA expression.Results Sevoflurane postconditioning significantly reduced infarct size in group Spo as compared with group I/R.There was no significant difference in area at risk between groups I/R and Spo.Myocardial I/R significantly increased the apoptotic index,Bcl-2 and Bax protein and mRNA expression in group I/R as compared with group S.Sevoflurane postconditioning significantly decreased apoptotic index and Bax protein and mRNA expression but increased Bcl-2 protein and mRNA expression in group Spo as compared with group I/R.Conclusion Sevoflurane postconditioning attenuates myocardial I/R injury by redncing myocardial apoptosis,up-regulating Bcl-2 expression and down-regulating Bax expression. Key words: Anesthetics, inhalation; Myocardial reperfusion injury; Apoptosis