间歇性低氧干预提高心梗大鼠心功能和运动耐量

目的:观察4周间歇性低氧（IH）干预对心梗（MI）大鼠心功能及运动耐量的影响。方法:28只雄性SD大鼠随机分为4组:空白组（Sham）、空白低氧组（Sham-IH）、心梗组（MI）和心梗低氧组（MI-IH）。低氧组放入低氧仓（模拟海拔5 000 m，氧浓度13%），每天4 h。对照组置于常氧环境中。干预4周后检测心肌AMPK表达，心梗面积比例，左心室射血分数和运动耐量。结果:同MI组比较，MI-IH组 （1） 心梗面积比例减少（P<0.001）；（2） 左心室射血分数增加（P<0.001）；（3） 运动耐量增加（P<0.001）；（4） AMPK表达增加（P<0.05）。结论:4周间歇性低氧干预能提高心功能和运动耐量，可能与心肌AMPK表达增加有关。

Intermittent hypoxia intervention improves cardiac function and exercise tolerance of rats with myocardial infarction

Objective: To explore the effects of four-week intermittent hypoxia (IH) intervention on cardiac function and exercise tolerance in rats with myocardial infarction (MI). Methods: Twenty-eight male SD rats were randomly divided into four groups: Sham group, Sham-IH group, MI group and MI-IH group. The IH groups were placed in the hypoxic chamber (simulates 5 000 maltitude, 13% oxygen concentration), at 4 h/d. The control groups were placed in normal environment. The AMPK expression, infarct size ratio, left ventricular ejection fraction and exercise tolerance were measured after 4-week intervention. Results: Compared with MI group, MI-IH group showed (1) decreased infarct size ratio (P <0.001)；(2) increased left ventricular ejection fraction(P <0.001)；(3) increased the exercise tolerance (P <0.001)；(4) increased the expression of AMPK(P <0.05). Conclusion: 4-week IH intervention can improve cardiac function and exercise tolerance in rats with MI, which may be related to AMPK elevation.