急性低氧家兔心率、血压变化及迷走神经作用机制的实验研究

THE CHANGES OF HEART RATE AND BLOOD PRESSURE IN RABBITS UNDER ACUTE HYPOXIA AND THE ANALYSIS OF VAGUS'ROLE NECHANISM

本文在麻醉制动家兔上观察了吸入11％低氧混合气30min及恢复过程中平均动脉血压(MAP)、心率(HR)的变化。迷走神经完整组(N=11)在低氧期间HR明显减慢,停止低氧后20min才能恢复。MAP在低氧5min时已下降,10、20、30min均明显低于对照值,停低氧5min既可恢复。HR减慢与MAP下降呈高度正相关。切断迷走神经组(N=7)HR的变化同完整组,MAP在低氧5—10min时明显高于对照水平,20—30min恢复到对照水平,停止低氧后维持不变。文中对有关机制进行了讨论。

The changes of heart rate(HR)and mean arterial pressure(MAP)during acute hypoxia Were studied in rabbits under the anesthetization and artificial respiration.The animals were divided into two groups:the control group with the intact vagus and the experimental group without the intact vagus.The HR in the con- trol group decteased remarkably at5,10,20and 30min of hypoxia(p<0.01),then reached to the control level at 20,30min after normoxia,the MAP reduced in hypoxia(p<0.01),but with a short recovering pe- riod after normoxia.In addition,a significant position correlation between the slow HR and the lower MAP (r=0.8991,p<0.001)was found,In the experimental group,the HR changes were similar to the control group during and after hypoxia,however,the MAP was significant higher than the ontrol level at 5,10min and equal to the control level at 20,30min of hypoxia and stayed at the control valueafter normoxia.The mechahism of the changes were discussedin the paper.