Evaluation of the effect of hydrogen sulfide postconditioning by P-V loop against myocardial I/R injury

Objective To evaluate the effect of hydrogen sulfide(H2S) postconditioning on myocardial ischemia-reperfusion(I/R) by pressure-volume loop(P-V loop).Methods The I/R model of rat in vivo was established by ligating the left anterior descending coronary artery for 30 min and reperfusing for 120 min.Wistar rats(n=32) were randomly divided into 4 groups: sham operation,ischemia-reperfusion(I/R),ischemic postconditioning(IPO) and H2S postconditioning.In sham operation,there was no ligation.In I/R group,the rats were suffered for 30 min of ischemia followed by 120 min of reperfusion.In IPO,three cycles of 30 s reperfusion and 30 s LAD reocclusion were administrated before reperfusion.In H2S postconditioning,NaHS(15 μmol/kg,sodium hydrosulfide) was administrated before coronary artery reperfusion.The heart rate(HR),I/R arrhythmia,the left ventricular end-systolic pressure (LVESP),left ventricular end-diastolic pressure(LVEDP),the slope of the end-systolic P-V relation(ESPVR) and the slope of the end-diastolic P-V relation(EDPVR) were detected.Infarct size was determined by scanning the images of the rat heart ventricular sections stained with Evans blue and TTC.Results Compared with I/R and IPO group,I/R arrhythmia and infarct size were decreased significantly(P0.05).The parameters of heart function evaluated by P-V loop were improved greatly(P0.01) in H2S postconditioning group compared with that in I/R group,but there was no significant difference between H2S postconditioning and IPO group.Conclusion Myocardial I/R injury can be decreased by H2S postconditioning,and it is sensitive and accurate to evaluate the heart function by P-V loop.