缺血预处理抗缺血再灌注心肌间质损伤的实验研究

Study of the protective effect of ischemic preconditioning on the myocardial interstitium in rats

目的：观察缺血预处理（ＩＰＣ） 对大鼠缺血再灌注心肌间质胶原及心肌功能结构关系的影响，以进一步探讨ＩＰＣ 对心肌的保护作用。方法：实验采用体重（２５０ ±３０）ｇ 雄性ＳＤ 大鼠２４ 只，分３ 组，每组８ 只，即假手术对照（ＳＣ）组；缺血再灌注（Ｉ／Ｒ） 组和缺血预处理（ＩＰＣ） 组。用超微结构立体计量及羟脯氨酸浓度测定观察心肌间质胶原变化，多道记录仪测量心功能指标，透射电镜观察心肌超微结构。结果：Ｉ／Ｒ 时心肌间质胶原浓度显著低于ＳＣ 组（ Ｐ＜ ０－０１） ，心肌超微结构损伤严重，左室功能明显低于ＳＣ 组（ Ｐ＜ ０－０１） 。ＩＰＣ 组心肌超微结构破坏明显低于Ｉ／ Ｒ 组。同时，心肌间质胶原浓度、胶原纤维线密度及左室功能指标明显高于Ｉ／Ｒ 组（ Ｐ＜ ０－０５ ，Ｐ＜ ０－０１） 。结论：ＩＰＣ 的心肌保护作用不仅表现在对心肌细胞上，而且对心肌间质也有重要的保护作用。

AIM:To further explore the effect of ischemic preconditioning on myocardium by observing the relations between myocardial interstitium and left ventricular functions. METHOD:24 male SD rats, weighting (250±30)g,were divided into 3 groups, sham operation (SC) group, ischemic/reperfusion (I/R) group, and ischemic preconditioning (IPC) group, each group consists of 8 rats. The collagenous fibers of myocardial interstitium were determined by ultrastructure morphometry and content of the hydroxyproline was measured. The left ventricular functions were observed by the multipolar recording instrument;Myocardial ultrastructure was observed by H—600 electron microscope. RESULTS:The collagenous fibers of myocardial interstitium were greatly reduced; injury of ultrastructures were serious and left ventricular function index were lowered in I/R group as compared with SC group. They were consistent. Underlying ischemic preconditioning, myocardial ultrastructure was improved obviously; myocardial collagen content, length density of collagenous fibers and index of the left ventricular functions were increased significantly ( P <0.05, P <0.01, vs I/R group).CONCLUSION:The beneficial effect of ischemic preconditioning on myocardial structure and function is related to its protective effect on myocardial interstitium.