THE EFFECT OF DESOXYCORTICOSTERONE ACETATE ON EARLY PREGNANCY1

Abstract

Daily injns. of 2 mg. of desoxycorticosterone acetate begun the day of mating in albino mice prevented implantation of embryos. Blastocysts were flushed from long, thin, hypoemic uteri as late as 11 days post coitum. Increased luteinization and vascularity were apparent up to approx. 72 hrs., after which time regression of the corpora lutea was progressive. These results duplicated those following previous expts. with testosterone propionate, but it was probable that these effects were andromimetic rather than androgenic. However, when the first inj. was delayed until approx. 40 hrs. after ovulation, embryos were implanted, with increased luteini- zation and vascularity in evidence throughout the period of observation, 7 days. Implantation was attributed to estro-genic pretreatment of the uterus in the delayed series. Continued growth of embryos in the delayed-injection series seemed dependent upon the progestational activity of desoxycorticosterone acetate, since cessation of injs. resulted in death of embryos and corpora luteal regression. These results indicated that the adrenal cortex might be an important factor in early pregnancy.