Effects of sevoflurane preconditioning and postconditioning on reperfusion arrhythmia of isolated rat heart

Yu Yang; Ma Jun

doi:10.3760/cma.j.issn.1673-4777.2017.01.004

Abstract：Objective To investigate the effects of sevoflurane preconditioning(SevoPC) and postconditioning(SevoPoC) on reperfusion arrhythmia of isolated rat heart.Methods Fifty SD rats were set up as isolated heart perfusion models and randomly divided into 5 groups,with 10 rats in each group.In control group,isolated hearts were treated with preoxygenated KH constant perfusion for 110 min.In ischemia-reperfusion injury(I/RI) group,KH was withdrawn for 20 min after 30 min perfusion and reperfused for 60 min to establish I/RI models.In SevoPC group,isolated hearts were treated with KH with 3％ sevoflurane constant perfusion for 15 min after 15 min KH perfusion to establish I/RI models.In SevoPoC group,KH was withdrawn for 20 min after 30 min perfusion,KH with 3％ sevoflurane was perfused for 15 min and preoxygenated KH was perfused for 45 min.In sevoflurane preconditioning with postconditioning(PCPo) group,KH with 3％ sevoflurane was perfused for 15 min after 15 min KH perfusion,then perfusion was suspended for 20 min,KH with 3％ sevoflurane was reperfused for 15 min and preoxygenated KH was perfused for 45 min.Heart rate (HR),left ventricular developed pressure (LVDP),maximum LVDP increase rate(± dp/dt),maximum LVDP decrease rate(-dp/dt) and left ventricular end-diastolic pressure(LVEDP) were measured.Myocardial infarct size and cardiac tropon I(cTnI) in coronary flow were tested.Reperfusion arrhythmia was recorded.Protein and gene expression levels of L-type calcium channel (LTCCs),ryanodine receptor 2 (RyR2) and sodium-calcium exchanger 1 (NCX1) were determined by western blotting and polymerase chain reaction.Results LVDP,± dp/dt,-dp/dt,HR in SevoPC group,SevoPoC group,PCPo group were significantly higher and LVEDP were significantly lower than those in I/RI group 30,60 min after reperfusion(P ＜ 0.05).Myocardial infarct size and cTnI level in SevoPC group and SevoPoC group were significantly lower than those in I/RI group [(17.9 ± 2.1) ％,(17.2 ± 2.3) ％ vs (23.8 ± 2.1) ％;(0.061 2 ± 0.002 0),(0.059 2 ± 0.003 1) mg/L vs (0.113 4 ± 0.004 3) mg/L] (P ＜ 0.05).Times of ventricular extrasystole,attack durations of ventricular tachycardia and ventricular fibrillation,incidences of ventricular fibrillation and reperfusion arrhythmia scores in SevoPC group and SevoPoC group were siginificantly lower than those in I/RI group (P ＜ 0.05).Protein expression levels of RyR2 in SevoPC group,protein expression levels of LTCCs,RyR2,NCX1 and gene expression levels of RyR2,NCX1 in SevoPoC group were siginificantly lower than those in I/RI group (P ＜ 0.05).Conclusion SevoPC and SevoPoC can improve heart function after I/RI and reduce the occurrence of reperfusion arrhythmia of isolated rat heart;the mechanism may be associated with the inhibition on LTCCs,RyR2 and NCX1.