The differential effects of estrogen and progesterone on the uterus of the ovariectomized golden hamster

Abstract

The effects of estrogen and progesterone on incorporation of ³H-thymidine by the uterus of the ovariectomized hamster are reported. In the ovariectomized hamster progesterone alone did not induce incorporation of ³H-thymidine. Estrogen alone caused significant incorporation of ³H-thymidine, predominantly in the luminal epithelium whereas a prior or subsequent treatment with progesterone activated DNA synthesis in the stroma and muscularis. These results indicate the role of estrogen in priming the uterus of the hamster for the subsequent action of progesterone.