小鼠急性重复低氧时中枢神经系统的功能变化

Functional Changes in Central Nervous System during Acute and Repetitive Exposure to Hypoxia in Mice

本工作观察小鼠在4或5次重复缺氧过程中各次缺氧耐受时间和中枢神经系统（CNS）机能的变化。结果表明，随着缺氧次数的增多，缺氧耐受时间进行性延长；主动活动和翻正反射逐渐消失；喘呼吸出现时间逐次推迟，心率和呼吸率进行性降低。戊巴出妥钠麻醉使前三次缺氧的耐受时间增加，但对后二次的耐受时间无何影响；咖啡因则使各次的耐受时间均显著缩短。结果提示，CNS抑制的进行性增强和循环呼吸活动的进行性降低参与重复缺氧过程中缺氧耐受性进行性增高的形成。

Tolerance times and functional changes in the central nervous system(CNS)were observed when mice were repeaedly exposed to auto-hypoxic hypoxia for 4 or 5 runs. The tolerance time,as usual,increased progressively as the number of exposure runs increased. Active activity and righting reflex gradually disappeared and the appearance of gasping rspiration was delayed in later exposure runs. Concurrently,the pulse rate and respiration rate progressively decreased. Pentobarbital anesthesia increased tolerance time during the first 3 exposure runs but had no effect on the fast 2 runs,whereas the tolerance lindt was significantly reduced for all runs by caffeine.Tht results suggest that progressive increase of inhibition in the CNS and progressive reduction in circulatory and respiratory activity might be involved in the progressive increase of tolerance to hypoxia during repeitive hypoxic exposure.