钾离子通道开放剂对老年大鼠心肌保护作用的实验研究

The myocardial protection of nicorandil,an opener of potassium channels on senile rat heart

目的 :探讨钾离子通道开放剂 (Nicorandil)对老年大鼠心肌缺血再灌注损伤的保护作用。方法 :在老年大鼠离体心脏的改良工作模型上 ,观察St.Thomas液 (S组 )、含 2 0 μmol/L钾离子通道开放剂Nicorandil的超极化停搏液 (N组 )和Nicorandil强化的St.Thomas液 (S +N组 )对老年大鼠进行低温缺血再灌注后的保护效果。结果 :缺血再灌注 30min后冠脉流量 (CF)恢复百分率、左室压力微分 (±dp/dt)及收缩压、舒张压恢复百分率S +N组明显优于S、N组 (P <0 0 5 ) ;灌注停跳液后心肌电活动和机械活动的消失时间S组少于N、S +N组 (P <0 0 1) ;再灌注后乳酸脱氢酶 (LDH)、磷酸肌酶同工酶(CK MB)漏出量及心肌含水量 3组间无明显差异。结论 :Nicorandil可增强老年大鼠心肌在缺血再灌注后的左室功能恢复 ,但延长心肌电、机械活动消失时间。因此 ,它对老年心肌的保护作用尚有待进一步研究。

Objective:This is to investigate the cardioprotective effects of Nicorandil,an opener of potassium channels on senium rat heart from ischemic reperfusion injury.Method:With a modified working model of isolated perfused heart of senium rat,the hearts underwent 2 hours of global hypothermic ischemia followed by 60 minutes of reperfusion.During ischemia,three groups of cardioplegic solutions were administered:(1) St.Thomas' solution (group S),(2) 20 μmol/L nicorandil(group N),(3) St.Thomas' solution plus nicorandil(group S+N).The preischemia and postischemia myocardial functions were assessed by the percentage recovery of ±dp/dt max ,coronary blood effluent(CBE) and water content.Results:The percentage recovery of left ventricle compliance,coronary blood effluent were significantly better in group S+N,N than in group S.The arresting time of electric,mechanic activity were longer in group S+N,N than in group S.Conclusions:Nicorandil could improve the compliance of left ventricular in postischemic aged rat,but could prolong the arresting time.So investigations on the aged cardiaprotection should be advanced in the future. [