THE MECHANISM OF THE EXPRESSION OF TOLERANCE FOR ISCHEMIA BY ISCHEMIC PRECONDITIONING IN FETAL BRAIN.

[目的]探讨缺血预处理与胎脑缺血耐受的关系，探讨缺血预处理诱导胎脑缺血耐受的机制。[方法]在10只胎羊慢性缺血性脑损伤模型上，采用反复脐带阻断的方法进行缺血预处理，再用反复脐带阻断的方法诱导胎羊脑缺血和缺氧，并分别加入腺苷激动剂和腺苷拮抗剂。[结果]缺血预处理可增强胎脑缺血耐受性，腺苷激动剂可部分增强缺血耐受性，腺苷拮抗剂可减弱缺血耐受性。[结论]缺血预处理可提高胎脑缺血耐受性，这种耐受性至少部分受腺苷调节。

[PURPOSE] The purpose of this study is to examine the relationship between ischemic preconditioning and ischemic tolerance in fetal brain, and evaluated the mechanism of the expression of the tolerance for ischemia by ischemic preconditioning.[METHOD] We performed ischemic preconditioning by repeated umbilical cord occlusion, and then inducted fetal brain ischemia and hypoxia by repeated umbilical cord occlusion in ten chronically instrumented fetal sheep with and without adenosine agonists and antagonists.[RESULTS] Fetal brain tolerance for ischemia was enhanced by ischemic preconditioning, which was partially augmented by adenosine agonists and diminished by adenosine antagonists.[CONCLUSION] Ischemic preconditioning elicits fetal brain tolerance for ischemia, which was at least in part regulated by adenosine.