缺氧和营养不良对大鼠膈肌肌电图及功能的影响及红景天保护膈肌功能作用的实验研究

目的：探讨慢性缺氧和营养不良对膈肌肌电图（EMGdi）和膈肌功能的影响及三普红景天保护膈肌功能的作用;方法：将32只Wistar大鼠随机分为慢性缺氧组（模拟海拔5000m，每日8小时，A组）、营养不良组（每日进正常食量1／2，B组）、缺氧加红景天组（缺氧方法同A组，每日缺氧前灌服三普红景天1.0g·kg-1，C组）和正常对照组（D组），每组8只。5周后在麻醉下测体重、EMGdi和膈肌功能，处死后测膈重;结果：B组体重低于A、C、D组50％，其膈肌显著变薄，面积缩小，重量减轻。A、B组EMGdi的H／L、Fc和电刺激时膈肌最大收缩力、最大强直收缩、疲劳指数均较C、D组显著降低，强直收缩时间和疲劳时间较C、D组显著缩短，A组与C、D组和B组与C、D组之间比较均有非常显著性差异（P均＜0.01），A组与B组和C组与D组比较无显著差异;结论：慢性缺氧和营养不良能明显引起膈肌疲劳，三普红景天具有明显保护缺氧性膈肌疲劳的作用。

EFFECTS OF HYPOXIA AND NUTRITIONAL DEPLETION ON DIAPHRAGM ELECTROMYOGRAPHY AND FUNCTION AND PROTECTIVE EFFECT OF HONG JING TIAN ON DIAPHRAGMTIC FNCTION IN RATS

To study the relationship of diaphragmatic fatigue (DF) with chrinic hypoxia and nutritional depletion and the protective effect on Hong Jing Tian on diaphragmatic function in rats. Methods: 32 wistar rats were randonly divided into four groups,group A in which rats were exposed to 5000 simulating altitude for 8 hours daily,group B in which nutritional depletion was performed by half normal feeded agent daily,group C in which chronic hypoxia was performed as group A and 1.0g .kg/day of Hong Jing Tian was infused to the stomach of rats before hypoxia,and group D as control. The electromyography of diaphragm (FMGdi)and its function were measured in total of rats after test 5 weeks. Results: H/I and Fc of EMGdi, maximal contraction,tetanic contraction, tetanic contraction time,contraction index and fatigue index of diaphragm in group A and B were significantly lower than those in group C and D. There were remarkable difference between both group A and Band both group C and D. (P<0.01 in all of parameter). Conclusions:The chronic hypoxia and nutritional depletion could result in DF,Hong Jing Tian would resistant this fitigue effect in hypoxic rats.