吡那地尔介导超极化心脏停搏液对心肌的保护作用

Myocardial preservation effects of hyperpolarized heart arrest induced by pinacidil

目的 为了提高心脏停搏液的心肌保护作用 ,探讨含吡那地尔 (pinacidil)超极化心脏停搏液对心肌的保护作用。 方法 32只新西兰兔根据体外循环中使用不同的心脏停搏液分为对照组和实验组 ,对照组用 St Thom as 号心脏停搏液 ,实验组用含吡那地尔 (5 0 μm ol/L)的心脏停搏液。两组又根据主动脉阻断后是否再灌注 ,分别分为两组 (对照组 A、对照组 B、实验组 A、实验组 B) ,每组 8只兔。对照组 A和实验组 A在主动脉阻断 6 0分钟后结束实验 ;对照组 B和实验组 B于主动脉阻断 6 0分钟、复灌 30分钟结束实验。记录心脏电机械停搏时间 ,复跳时的心律失常情况 ,测定实验结束时各组心肌三磷酸腺苷 (ATP)、总腺苷酸 (TAN)、Ca2 +、丙二醛 (MDA)含量 ,对照组 B和实验组 B血清心肌酶含量 ,并观察心肌超微结构变化。 结果 4组心脏均迅速发生电机械停搏 ,对照组 B、实验组 B复跳时均发生心律失常 3例 ,未发生严重心律失常 ;实验组 A和实验组 B的 ATP、TAN分别高于对照组 A和对照组 B(P<0 .0 1) ,而 Ca2 + 和 MDA分别显著低于对照组 A和对照组 B(P<0 .0 5 ) ,实验组 B心肌酶的漏出量显著低于对照组 B(P<0 .0 1)。实验组 B超微结构损伤轻 ,优于对照组 B。 结论 含吡那地尔的心脏停搏液对心肌保护的作用优于高

Objective To approve the myocardial preservation effect of cardioplegia and to investigate the effect of pinacidil on myocardial preservation as a cardioplegia agent. Methods According to different cardioplegia, 32 New Zealand rabbits were divided into control group and experimental group. Using St Thomas Ⅱ solution in control group, pinacidil cardioplegia(50μmol/L) in experimental group. The two groups were respectively divided into two subgroups (control A, control B and experimental A, experimental B ),based on whether being reperfused after aorta occluded. There were 8 rabbits each group. The experiments ended after aorta occluded for 60 minutes in control A and experimental A,those of control B and experimental B ceased at the time of reperfusing 30 minutes after aorta occluded for 60 minutes. The time to mechanical and electrical arrest were recorded; rhythm was observed during reperfusion; at the end of experiments,myocardial adenosine triphosphate (ATP), total adenosine nucleotide (TAN),Ca 2+ and malondiahyde (MDA) were determined; myocardial enzyme were determined in control B and experimental B; myocardial ultramicrostructure was observed. Results The hearts of four groups rapidly fell into mechanical and electrical arrest,the numbers of arrhythmia in control B was the same as in experimental B (3 cases), without malignant arrhythmia; the myocardial ATP and TAN of experimental A and experimental B were obviously higher than those in control A and control B ( P< 0.01), while Ca 2+ and MDA significantly less ( P< 0 05), myocardial enzyme in experimental B were lower than those in control B ( P< 0.01); myocardial ultramicrostructure damage in control B group was more serious than in experimental B. Conclusion The effect on myocardial preservation of pinacidil hyperpolarical cardioplegia solution is superior to that of St Thomas Ⅱ solution.