Endocrinology, Vol 108, 1321-1327, Copyright © 1981 by Endocrine Society

ARTICLES

Effects of human chorionic gonadotropin in the rabbit corpus luteum: loss of estrogen receptor and decreased steroidogenic response to estradiol

KC Yuh and PL Keyes

The effects of hCG on luteal estrogen receptor and steroidogenesis were examined in 9-day-pseudopregnant rabbits. Twenty-four hours after the injection of ovulatory dosages of hCG (10-100 IU), a dose-related loss of luteal estrogen receptor and in vitro progesterone production was observed. The declining progesterone production was not due to the increased conversion of progesterone to the major metabolite, 20 alpha- dihydroprogesterone. The loss of steroidogenesis induced by hCG was not permanent and could be reversed by estradiol treatment started within 24 h of hCG injection. In those animals with a higher luteal estrogen receptor content at the start of the estrogen treatment, the steroidogenic response was greater. These findings indicate that hCG- induced loss of steroidogenesis is associated with the loss of luteal estrogen receptor. The degree of restoration of progesterone synthesis induced by a 24-h period of estradiol treatment may be related to the content of unoccupied cytoplasmic estrogen receptor in the corpus luteum.

This article has been cited by other articles:

				J. M. Bowen and P. L. Keyes The Proestrous Prolactin Surge Is Not the Sole Initiator of Regressive Changes in Corpora Lutea of Normally Cycling Rats Biol Reprod, November 1, 1999; 61(5): 1208 - 1215. [Abstract] [Full Text]

				R. Misao, Y. Nakanishi, W.S. Sun, J. Fujimoto, S. Iwagaki, R. Hirose, and T. Tamaya Expression of oestrogen receptor {alpha} and ß mRNA in corpus luteum of human subjects Mol. Hum. Reprod., January 1, 1999; 5(1): 17 - 21. [Abstract] [Full Text] [PDF]