急、慢性缺氧对大鼠心功能的影响

Effects of Acute Hypoxia and Hypoxic Acclimatization on Cardiac Functions of Rats.

目的研究急性缺氧和慢性适应性缺氧对大鼠心脏收缩和舒张功能的影响。方法间断低氧习服大鼠（３０００ｍ、５０００ｍ各２ｗｋ，４ｈ／ｄ）和正常大鼠经８０００ｍ缺氧４ｈ后，观察其整体心功能。结果与常氧对照组相比，急性缺氧大鼠左心室反映收缩功能的指标ＬＶＳＰ，＋ｄｐ／ｄｔｍａｘ，Ｖｐｍ，Ｖｍａｘ及反映舒张功能的指标ｄｐ／ｄｔｍａｘ均显著降低，经慢性适应性缺氧后，大鼠左心室舒缩功能的各项指标虽仍低于常氧对照组，但显著高于急性缺氧组。结论急性重度缺氧可显著抑制心功能，动物经低氧适应后，心脏功能明显改善，可减轻缺氧对心脏的损伤。

Objective To study the effects of acute hypoxia and intermittent hypoxic acclimatization on cardiac systolic and diastolic functions in rats. Method Cardiac functions were investigated after intermittent hypoxic acclimatizated (3000 m and 5000 m,2 wk respectively,4 h/d) and normoxic rats were exposed to hypoxia (8000 m) for 4 h. Result The systolic functional parameters such as LVSP, +dp/dt max ,Vpm,V max and the diastolic functional parameter -dp/dt max of acute hypoxic rats were reduced significantly as compared with normoxic control rats. After hypoxic acclimatization, the left ventricular functions of rats were increased significantly as compared with those of acute hypoxic rats. But they were still lower than those of normoxic control rats. Conclusion Acute hypoxia can affect cardiac functions and hypoxic acclimatization can alleviate the hypoxic effects on cardiac functions.