St.Thomas 心脏停搏液对成年和幼年兔心肌缺血—再灌注损伤保护作用的比较

A Comparative Study on the Response to St.Thomas Cardioplegic Solution in Neonatal and Adult Isolated Rabbit Heart During Ischemia Reperfusion

目的：比较Ｓｔ．Ｔｈｏｍａｓ心脏停搏液对成年和幼年兔心肌缺血—再灌注损伤的保护效果。方法：雄性成年和幼年白兔离体心脏，用Ｌａｎｇｅｎｄｏｒｆ装置灌流，预灌后行缺血—再灌注试验，于缺血期间施加Ｓｔ．Ｔｈｏｍａｓ停搏液，观察心肌功能和超微结构的变化。结果：在冠状动脉流量、心肌收缩幅度和静息张力的恢复百分率以及超微结构方面，Ｓｔ．Ｔｈｏｍａｓ停搏液对成年兔心肌均有良好的保护作用，但对幼年兔心肌的保护效果不显著。结论：初步证实Ｓｔ．Ｔｈｏｍａｓ停搏液对幼年兔心肌缺血—再灌注损伤的保护效果比成年兔差。

Objectives:To determine whether St.Thomas cardioplegic solution for preservation of the immature myocardium is as effective as that of the mature myocardium during ischemia/reperfusion. Methods:Sets of 60 hearts from immature (3 to 4 weeks,500 g) and mature (24 weeks,2 kg) rabbits were subjected to 120 min of ischemia and 30 min of reperfusion using Langendorff perfusion.Myocardial protection consisted of infusion of cardioplegic solution every 30 min at 4℃ in a dose of 10 ml/kg of body weight and maintenance of hypothermia at 10℃ by immersion of heart in a cold saline bath. Results:The recovery percentages of preischemia cardiac output,resting tension and contractile extent were lower in the immature than in the mature during 1,2,3,4,10,15,20,25,30 min of reperfusion after 120 min of ischemia,respectively.Furthermore,the ultrastructure damage in the immature myocardium was apparent. Conclusion:It is preliminarily evident that St.Thomas cardioplegic solution does not provide adequate preservation of the function and morphological structure in the immature myocardium.