STUDIES ON THE TERMINATION OF PREGNANCY WITH NORETHYNODREL

Publisher Website
Google Scholar
Abstract
SUMMARY: An intraperitoneal injection of 0·3 mg. norethynodrel on day 2 post coitum significantly diminished the rate of nidation among ovariectomized mice supplemented with progesterone and oestradiol. Presence of the ovary partly mitigated this action. The factor of greatest quantitative significance involved in impeding nidation was found to be that responsible for decreasing the recovery of blastocysts from the uterus. Evidence implicating tubal locking was sought, but not obtained. Degenerated blastocysts were recovered from the uterus, but only infrequently. Results of studies involving transplantation of blastocysts to ovariectomized pseudopregnant hosts revealed that the rate of nidation among recovered blastocysts was only slightly affected in one of two experiments by treatment of the donor with norethynodrel. However, a dose of 0·6 mg. norethynodrel given to the host 2 days after induction of pseudopregnancy elicited a response that almost completely inhibited nidation. Norethynodrel was found to counteract the deciduomagenic action of progesterone on the rat uterus. The steroid caused extensive foetal resorption in intact and ovariectomized mice when given intraperitoneally in a dose of 2 mg./day from days 8–10 p.c.

This publication has 0 references indexed in Scilit: