ACTIVITY PROFILE OF PLACENTAL SUPEROXIDE-SUPEROXIDE DISMUTASE SYSTEM IN PREGNANT MICE AND ITS POSSIBLE RELATION WITH PLACENTAL STEROIDOGENESIS

Placenta in mouse generate increasing quantities of superoxide dismuta se from day 13 of pregnancy until parturition. This is associated with a concomitant reduction in the activity of superoxide radical. This f indings points to the steroidogenic control of the later half of pregn ancy by the placental axis. Parturition is associated with an abrupt s purt in superoxide radical. This is a novel finding and could be a con sequence of the estrogen surge at labour. It is suggested that this ab rupt increase in superoxide radical level at parturition may remould t he placental membrane fluid at the point of its attachment with uterin e membranes so as to facilitate the separation of placenta from uterus .