The protective effect of prenatal hypoxia adaptation on the brain of newborn rat / 中华麻醉学杂志

ABSTRACT

Objective To examine whether the prenatal hypoxia adaptation has any protective effect on the brain of the newborn rat Methods 12 22 day pregnant Wistar rats were randomly divided into 2 groups the control group and the treated group In the treated group the pregnant rats were placed in a tightly closed hypoxia adaptation chamber When the O 2% in the chamber dropped to 15%, the rat was taken out to breathe fresh air for 5 min then put back in the chamber This process was repeated until its natural delivery In control the chamber was not tightly closed (O 2%=21%) 40 newborn rats weighing 6 8g were selected and subjected to brain ischemia and hypoxia, Left common carotid artrey was ligated under ether anesthesia 2h after recovery from surgery the newborn rats were placed in hypoxia chamber (T=36℃?1℃,O 2%=9%)for 1 5h 24h later they were sacrificed and brain was removed for microscopic examination (optical and electron) and flow cytometry measurement Results In the treated group most newborns were normal There were a few apoptosis cells in early stage The rate of apoptosis was 2 9%, necrosis cells could hardly be seen In the control group, although most neurons were also normal but there were apoptosis cells in early, middle and late stage and even necrosis cells The rate of apoptosis was 9 51%, which was significantly different from that in the treated group Conclusions Prenatal hypoxia adaptation has protective effect on the brain of newborn rat