Comparative Effects of Ovarian Steroids on Glycogen Metabolism of Rat, Rabbit and Guinea Pig Uterine Tissue

Abstract

SummaryThe effects of the ovarian steroids, estrogen and progesterone on uterine glycogen metabolism in the rat, guinea pig and rabbit were compared. Estrogen caused a uterine glycogenic response in all three species which was maximal, 48 hr following the initiation of treatment to adult ovariectomized females. Progesterone treatment to these animals following a 48-hr estrogen prime elicited a significant increase in uterine phosphorylase activity in the guinea pig and rabbit but had no effect on rat uterine phosphorylase. Studies on the individual components of the rabbit uterus (myometrium and endometrium) in response to estrogen and progesterone revealed different effects in uterine glycogen metabolism. The myometrium was more responsive to estrogen while the endometrium was more responsive to progesterone in terms of uterine glycogenesis. These findings suggest that different cell types within the uterus respond differently to different steroids depending on the endocrine state of the animal.