缺血预处理结合心麻痹液保护未成熟兔心肌的效果

Protective Effects of Ischemic Preconditioning Combined with Cold Crystalloid Cardioplegia on Immature Myocardium in Isolated Rabbit Heart

目的 探讨缺血预处理 (IPC)结合心麻痹液对未成熟兔心肌的保护作用。 方法 采用体外左心作功模型 ,比较缺血 5 min再灌注 5 min的缺血预处理加 ST.Thom as 液 (IPC组 )和仅 ST.Thomas 液 (对照组 )对幼兔 (3～ 4周 )心脏缺血再灌注后心脏功能、冠脉微循环、能量代谢及超微结构的影响。 结果 IPC组心脏收缩功能、冠脉流量及阻力恢复更佳 ,冠脉流出液中的一氧化氮含量较高而内皮素较低 ,能量物质含量高 ,心肌细胞超微结构损害轻。 结论 缺血预处理结合心麻痹液对未成熟兔心肌提供更佳的保护。

Objective\ To investigated the protective effects of ischemic preconditioning(IPC) combined with cold crystalloid cardioplegia on reperfusion injury of immature myocardium.\ Methods\ An modified isolated working heart model was used.\ 20 hearts of immature rabbits(aged from 3 to 4 weeks) were randomly divided into two groups.\ Control group received intermittent ST.ThomasⅡ solution perfusion during 2\|hour global ischemia, IPC group received 5 minutes of global ischemia and 5 minutes of reperfusion before ST.ThomasⅡ solution perfusion.\ Recovery of heart postischemia function, levels of nitric oxide(NO) and endothelin(ET) of coronary effluent, myocardial water content, ATP content of myocardium and ultrastructural changes were evaluated.\ Results\ Recovery of heart postischemia contractility function, coronary sinus flow(CSF), coronary venous resistance(CVR) were significantly better in IPC group than those in control group.\ IPC group showed marked lower ET level and higher NO level of coronary effluent.\ The ATP content of myocardium was significantly higher in IPC group than that of control group, and ultrastructural damage of immature myocardium was very slight in IPC group.\ There was no difference in myocardial water content between the two groups.\ Conclusion\ Ischemic preconditioning as an adjunct to cold crystalloid cardioplegia produced better protection to myocardium in immature rabbit.