Dynamic observation on the apoptosis of brain cortex and hippocampus after acute hypobaric hypoxia in rats

Objective To observe the dynamic change of apoptotic rate of cells from brain cortex and hippocampus tissue after acute hypobaric hypoxia in rats Methods Thirty Wistar rats were divided into control group and 5 experimental groups The experimentals were exposed to 7500 m altitude in animal hypobaric chamber for 20 min, and brain tissues were taken 1 d, 2 d, 3 d, 4 d and 5 d after exposure for detection of percentage of cells of different stages and rate of apoptosis with flow cytometer Results The rate of apoptotic cell(BAD) from brain tissues of rats increased day by day after hypoxia exposure and the peak value was 3 d after exposure (hippocampus) and 4 d after exposure (cortex) BAD of brain tissue lowered 5 d after exposure but still higher, although non significantly than that of control group The changes of different stage of cells revealed the similar course Conclusions The apoptosis of brain peaked 3 or 4 day after acute hypoxic exposure According to the apoptotic rate, cortex is more sensitive to acute hypoxia than hippocampus