Optimal time choice of ischemia-reperfusion in the preparation of isolated heart injury model

OBJECTIVE To explore a suitable time for ischemia-reperfusion injury model preparation.METHODS The rat heart was isolated and perfused retrogradely using the Langendorff method at a constant pressure,the electrocardiogram(ECG),left ventricular pressure(LVP),coronary flow(CF),left ventricular end diastolic pressure(LVEDP),left ventricular end diastolic pressure(LVEDP),and the rate of arrhythmia were estimated and the left ventricular developed pressure(LVDP),maximum rate of increase in left ventricular pressure(+dp/dtmax),maximum rate of decrease in left ventricular pressure(-dp/dtmax) and the heart rate(HR) were calculated at 5,10,20 and 30 min.RESULTS Compared with pre-ischemia,the reperfusion caused significant decrease in CF and HR(P0.05) and a marked depression in cardiac function as indicated by an obvious decrease in LVDP,±dp/dtmax,and a marked elevation in LVED after reperfusion(P0.01).CONCLUSION The optimal time for model preparation is ischemia for 31 min followed by 30 min reperfusion.