The Protective Effects Of STH Solution Combined With HTK Solution On Long Time Ischemic-reperfusion Injury In Isolated Rat

To investigate the effects of STH solution combined with different dosage of HTK solution on ischemia reperfusion myocardium and its mechanism in isolated rat hearts, by modified Langendorff apparatus.40 female Wistar rats weighting 230 to 280g, were randomized as five groups (n=8):STH group (group S); HTK group (group H); STH+HTK10ml/Kg group (group S+H10); STH+HTK20ml/Kg group (group S+H20); STH+HTK30ml/Kg group (group S+H30).Langendorff ischemic-reperfusion model was developed by isolated rat after anesthesia, then found the aortic and perfused with 37℃Krebs-Henseleit Bicarbonate Buffer (KHB) solution 30 minutes, the perfusion pressure was 90cmH2O.Then cardiac arrest was induced by corresponding cardiopledic solution in each group, group S and group H was perfused with STH solution 15ml/Kg every 30 minutes or HTK solution 30ml/Kg once time, in the other three groups, STH solution was perfused as 15ml/Kg at first,then perfused HTK solution 10ml/Kg,20ml/Kg,30ml/Kg respectively, the perfusion pressure was also 90 cmH20. At the period of cardiac arrest, hearts were immerged in 25℃STH solution in group S but HTK solution in the other four groups for 120 minutes, then reperfused with 37℃KHB 30 minutes. Hemodynamic parameters were recorded just at immediate of cardiac arrest,15 minutes and 30 minutes after reperfusion,2ml of coronary flow was taken before the cardiac arrest and after reperfused 15min,30min to detect myocardial leak enzyme LDH, CK. Tissue at heart apexes was retented after experiment. It was detected ATP, MDA and SOD contents in myocardium.1.The influence on hemodynamic There were no significant differences of HR,LVDP,+dp/dtmax,-dp/dtmax among groups before hearts arrested(P>0.05).After reperfusion,HR,LVDP,+dp/dtmax,-dp/dtmax in each group had the tendency to decrease,HR,LVDP,+dp/dtmax,-dp/dtmax in group S+H20 and S+H30 were better than group S and S+H10(P<0.05),HR,LVDP in group H were better than group H and S+H10 (P<0.05),there was no statistic difference between group S+H20 and S+H30.2.The influence on the myocardial leak enzyme There were no statistic differences of LDH and CK among groups before the hearts arrested (P>0.05).After reperfusion, both LDH and CK had the tendency to increase, and they were lower in group S+H20 and S+H30 than group S,S+H10,H (P<0.05).Compared with group S, the contend of SOD and ATP in the other four groups were increased significantly (P<0.01) and the MDA decreased significantly as well (P<0.01).The contend of MDA in group S+H20 and S+H30 were lower than in group H (P<0.05); The contend of SOD in group S+H20 and S+H30 were higher than in group S and S+H10 (P<0.05).STH solution combined with certain dosage of HTK solution can protect the myocardium from ischemic-reperfusion injury, improve the contraction force of ischemic-reperfusion myocardium, increase the contend of ATP,SOD and decrease the contend of CK,LDH,MDA, lighten the myocardium injury in some degree.