Yamada T, Takagi M, Kugimiya T, Miyagawa N, Shibata R, Hashiyada H, Yamaguchi H
Department of Cardiovascular Surgery, Nagasaki University School of Medicine, Japan.
Heart Vessels. 1995;10(6):310-7. doi: 10.1007/BF02911389.
The effects of Na+ and Ca2+ concentrations in the reperfusate on post-ischemic myocardial recovery were examined. Also, the myocardial protective effects of amiloride, an inhibitor of the Na+/Ca2+ and Na+/H+ exchange systems, added to cardioplegic solutions were assessed, using an isolated working rat heart perfusion system. Global myocardial ischemia was induced by 30-min normothermic cardioplegic arrest, using St. Thomas' solution. The concentration of Na+ in the reperfusate varied, stepwise, from 75 to 145 mM/l, and that of Ca2+, from 0.1 to 2.5 mM/l. In this study post-ischemic functional recovery was best at 110mM/l Na+ and 1.2-1.8 mM/l Ca2+ in the reperfusate. A significantly greater post-ischemic functional recovery and a lower creatine kinase release were observed when amiloride was added to the cardioplegic solution. Ca2+ overload via Na+/Ca2+ and Na+/H+ exchange systems would, thus, appear to be due, at least in part, to post-ischemic reperfusion injury.
研究了再灌注液中Na⁺和Ca²⁺浓度对缺血后心肌恢复的影响。此外，使用离体工作大鼠心脏灌注系统，评估了添加到心脏停搏液中的钠/钙和钠/氢交换系统抑制剂阿米洛利的心肌保护作用。采用圣托马斯液，通过30分钟常温心脏停搏诱导全心缺血。再灌注液中Na⁺浓度从75 mM/l逐步变化至145 mM/l，Ca²⁺浓度从0.1 mM/l变化至2.5 mM/l。在本研究中，再灌注液中Na⁺浓度为110 mM/l、Ca²⁺浓度为1.2 - 1.8 mM/l时，缺血后功能恢复最佳。当在心脏停搏液中添加阿米洛利时，观察到缺血后功能恢复明显更好，肌酸激酶释放更低。因此，通过钠/钙和钠/氢交换系统的Ca²⁺超载似乎至少部分是由于缺血后再灌注损伤所致。
