Expression of heat shock protein 70 in the brain tissue of fetal and newborn rats after prenatal hypoxic adaptation / 中华麻醉学杂志

ABSTRACT

Objective To investigate the change in heat shock protein 70(HSP7O) in the brain tissue of fetal and newborn rats after prenatal hypoxic adaptation and the possible mechanism of the protective effect. Methods Twenty-two 22d pregnant Wistar rats were randomly divided into two groups: GroupⅠ(hypoxic adaptation group) and group Ⅱ(control group). The animals in group Ⅰ were placed in a tightly closed hypoxic adaptation chamber, of which the oxygen and carbon dioxide concentrations were monitored. The pregnant rats were taken out and exposed to fresh air for 5 mm when the 02 % in the chamber was reduced to 15 %, then the pregnant rats were placed back in the chamber and the above process was repeated once. The animals were then left for their natural labor. In control group the pregnant rats underwent the same process but the chamber was not tightly closed(O2 %= 21 %). Prenatal rats were delivered by cesarean section at lb. 3h, 8h, 24h, 48h, 72h, 120h and 168h after hypoxic adaptation and decapitated and brain was removed. Seven newborn rats from each group were decapitated and brain was removed for determination of HSP70 expression with immunohistochimical technique. Results No HSP7O expression was observed in the brain tissue of normal prenatal and newborn rats. HSP70 was observed in the different regions of hippocampus and cortex from 8h to 168h after hypoxic adaptation. Strongest HSP70 expression was observed in hippocampus CAl . Conclusions HSP70 plays a role in the formation of prenatal hypoxic adaptation.