梯度降压缺氧预激对小鼠心肌缺氧耐受性影响及其机制初探

Effects of repetitive Hypoxia Preconditioning on Myocardial Tolerance to Hypoxia of Mice

[目的]：探讨反复缺氧预激对小鼠缺氧耐受性的影响及其可能机制。[方法]：用正常小鼠及经五次梯度降压缺氧预激小鼠分别制备血浆及心肌匀浆。将来自正常小鼠及预激小鼠的血浆分别注入两组正常小鼠腹腔（Non－PP组和PP组），将来自正常小鼠及预激小鼠的心肌匀浆分别注入另两组正常小鼠腹腔（Non－PH组和PH组）。各小鼠分别于注射后30min置于28．7KPa低压缺氧环境下测心电活动时间（CEAT）。[结果]：PH组CEAT比Non－PH组延长1．80倍（P＜0．01），PP组CEAT比Non－PP组延长1．29倍（P＜0．01）。[结论]：反复梯度降压缺氧预激能明显增强小鼠心肌的缺氧耐受性，该作用与反复缺氧预激促使机体各组织器官产生某些具有可转移性的保护性物质有关。

This study was to explore effects of repetitive hypoxic preconditioning on the myocardial tolerance to hypoxia of mice and its possible mechanism. [METHODS ] Use normal mice and the mice preconditioned by grade-declined hypoxia for five times to pre pare plasm and myocardial homogenate re spectively, then inject plasm from normal and preconditioned mice P. I (peritoneal) in jection into two groups of normal mice (Non-PP group and PP group)respectively,inject hornogenate from normal and precon ditioned mice P. I. into two other groups of normal mice (Non-PH group and PH group) respectively,and observe the change of cardioelectric activation time CEAT 30min after injection under the air pressure of 28. 7Kpa. [RESULTS]:. The CEAT of PH group and PP group increased up to 1.8-fold and 1. 29-fold respectively compared with the corresponding Non-PH group and Non-PP group. [CONCLUSION ]: Repetitive hypoxic preconditioning under gradedeclined air pressure can improve the myocardial tolerance to hypoxia of mice. Thepossible mechanism might be that repetitivehypoxia preconditioning induces heart toproduce some adaptive changes and someprotective and transtferable materials.