低氧适应对缺氧性心功能损伤的保护作用及其机制探讨

缺氧对心脏功能的影响与缺氧的严重程度、发生速度及时程有关。本实检比较了急性缺氧与阶梯适应性缺氧对Ｗｉｓｔａｒ大鼠心脏功能及心肌收缩蛋白Ｃａ２＋，Ｍｇ２＋－ＡＴＰ酶的不同影响，结果表明，低氧适应组与急性缺氧组比较，左右心室的±ｄｐ／ｄｔｍａｘ、收缩指数等心功能指标均有显著的改善，心肌收缩蛋白Ｃａ２＋，Ｍｇ２＋－ＡＴＰ酶活性也显著高于急性缺氧组。从而说明，动物经低氧适应后，心脏的代偿功能得到充分发挥，从面减轻缺氧对心脏的损伤。心肌收缩蛋白Ｃａ２＋，Ｍｇ２＋－ＡＴＰ酶的改善可能是心脏代偿机制的生物化学基础之一。

THE PROTECTIVE EFFECT OF HYPOXIC ACCLIMATIZATION ON CARDIAC FUNCTION DEFICIENCY DUE TO HYPOXIA AND ITS MECHANISM

The effect of hypoxia on cardiac function is related to the degree, the rate and the time course of hypoxia. In the present experiment the comparative effects of acute hypoxia and hypoxic acclimatization on cardiac function and the myofibrillar Ca2 , Mg2 -ATPase activity in rats were studied. The results showed that acute hypoxia resulted in significant damage of cardiac function. In contrast, there were compensated ventricular function and significantly increased myofibrillar Ca2 , Mg2 -ATPase activity after hypoxic acclimatization as compared with those after acute hypoxia. These results suggest that hypoxic acclimatization has obvious protective effect on damaged cardiac function due to hypoxia by elevating the Ca2 , Mg2 -ATPase activity of myocardial contraction protein.