Estrogen stimulation of conjugase activity in the uterus of ovariectomized rats

Abstract

Recent observations have indicated that uterine folic acid conjugase (pterolypolyglutamyl hydrolase) undergoes rhythmic variation during the reproductive cycle of the rat. In the present study conjugase activity and ratios of "total" folate to "free" folate were determined in uterine homogenates of ovariectomized rats, with ane without estrogen stimulation. An increase in conjugase levels and a relative increase in the "free" folate component occurred in castrated animals 12 to 18 hours following injection of 10 mug of estradiol-17beta.

PIP: Estrogen stimulation of conjugase activity in the uterus was studied in ovariectomized rats. The rats were sacrificed either without estrogen replacement or at varying time intervals after the sc administration of 10 mcg of estradiol 17-beta. The uterine horns were processed for folate determinations or for conjugase assay. A significant increase (p less than .001) of conjugase activity was seen in the animals sacrifieced 20 hours after administration of the hormone. The ratio of total-to-free folate was significantly lower (p less than .001) than the control 20 hours after injection of the hormone. The drop in both free and total folates could not be explained.