NICORANDIL改善心肌保存液保存效果的实验研究

目的：在离体鼠心Langendorff灌注模型上，检验心肌保存液中加入ATP－K离体通道开放剂Nicorandil对心肌保存液保存效果的影响。方法：实验分为4组，UW液组、HTK液组、UW液组＋Nicorandil组和HTK液＋Nicorandil组，每组8只Wistar雄性大白鼠。麻醉和抗凝后，快速取下鼠心并悬挂在Laupeudorff灌注模型上灌注，37℃下测定血流动力学基础值。分别用四种保存液灌停离体鼠心并低温（4℃）保存4小时。重新复温复灌，再次测定血流动力学值，留取标本分别测定心肌水含量、心肌酶漏出量、ATP和CP含量和心肌细胞超微结构变化。结果：心肌血流动力学恢复率，HTK液组高于UW液组；UW液＋Nicorandil组高于UW液组；HTK液＋Nicorandil组高于HTK液组；HTK液＋Nicorandil组 Nicorandil组低于HTK液组；UW液＋Nicorandil略低于UW液组，心肌中ATP和CP含量，HTK组高于UW组；HTK液＋Nicorandil组高于UW液＋Nicorandil组。心肌细胞超微结构变化，HTK液＋Nicorandil组心肌损害最轻，HTK组轻于UW液＋Nicorandil组，UW液组心肌损害最严重。结论：HTK液和UW液都是比较适合的心肌保存液，Nicorandil能够善心肌保存液的保存效果。

Experiment study of protection effect of Nicorandil in myocardial preservation solution

objective: Nicorandil(NCR) exerts its action as an ATP-sensitive potassium channel opener at low extracellular potassium concentration. we investigated the efficacy of using HTK solution and UW solution with NCR following 4 hours hypothermia preservation in the isolated rat heart mode. Method: Hearts isolated from male Wistar rats were mounted on a Langendorff apparatus to estimate baseline hemodynamic values. The hearts were divided into four groups(n=8 per group): Group1, UW solution; Group2, HTK solution; Group3, UW solution with Nicorandil; Group 4 , HTK solution with Nicorandil. They were arrested and stored at 4℃ in each preservation solution for 4 hours. After the cold storage, the hearts were reperfused and the recovery of myocardial function including Left Ventricular End-Diastolic Pressure(LVEDP), Left Ventricular Developed Pressure(LVDP), and the rate of change in Left Ventricular Pressure(+dp/dt, -dp/dt) ]were measured. Myocardial tissue water content was evaluated. Myocardial tissue Adenosine Triphosphate (ATP) and Creatine Phosphate(CP) content in each group were also measured just after cold storage. The leakage of myocardial enzymes were measured as well. Finally, myocardial ultrastructure was observed. Result:The recovery rate of myocardial function:The group of HTK was better than that in the group of UW (P<0.05); the group of HTK solution + Nicorandil was better than that in the group of HTK (P<0.05); The level of ATP and CP in myocardial tissue: the group of HTK was significantly better than that in the group of UW (P<0.01); HTK solution + Nicorandil was better than that in the group of HTK (P<0.05); group of HTK solution + Nicorandil was better than that in the group of UW solution with Nicorandil (P<0.05). There were no significant changes in the myocardial tissue water content of four groups; The leakage of myocardial enzymes: the group of HTK was better than that in the group of UW (P<0.05); The myocardial ultrastructure: The histological changes of myocardial cell and the damage to vascular endothelial cell were more significant in UW solution+nicorandil group compared with that in the HTK solution+nicorandil group. The histological changes were severer in UW solution group than that in the UW solution+nicorandil group. Conclusion:These results suggest that HTK solution is more effective than UW solution for myocardial preservation, and that NCR provides still better protection in the heart transplantation.