Endocrinology, Vol 108, 1425-1430, Copyright © 1981 by Endocrine Society

ARTICLES

Antireproductive effects of a potent GnRH antagonist in the female rat

C Rivier, J Rivier and W Vale

The administration of the potent gonadotropin-releasing hormone antagonist [Ac-dehydro-Pro1,pCl-D-Phe2,D-Trp3,6,N alpha MeLeu7]GnRH (Antag) to female rats results in disruption of the estrous cycle and gestation. Daily doses of 200 microgram Antag are completely effective in blocking regular cycles, which resume 6-9 days after cessation of treatment. When administered to mated female rats, Antag seems to be less effective in terminating pregnancy during the earlier (1-7 days) than later (7-12 days) days of gestation. This may reflect the inability of Antag to lower the secretion of PRL (the luteotropic hormone of early pregnancy) as compared to the Antag-induced inhibition of LH production (the luteotropic hormone of midpregnancy). As a result, administration of Antag 7-12 days after mating is accompanied by a decrease in plasma progesterone levels incompatible with the survival of the embryos. These data provide further evidence that the neutralization of the function of endogenous gonadotropin-releasing hormone is deleterious to reproductive integrity.

This article has been cited by other articles:

				M. Nekola, A Horvath, L. Ge, D. Coy, and A. Schally Suppression of ovulation in the rat by an orally active antagonist of luteinizing hormone-releasing hormone Science, October 8, 1982; 218(4568): 160 - 162. [Abstract] [PDF]

				D Heber, R Dodson, R. Swerdloff, K Channabasavaiah, and J. Stewart Pituitary receptor site blockade by a gonadotropin-releasing hormone antagonist in vivo: mechanism of action Science, April 23, 1982; 216(4544): 420 - 421. [Abstract] [PDF]