THE EFFECT OF METHYLOESTRONOLONE ON ENDOMETRIAL CARBONIC ANHYDRASE AND ITS ABILITY TO MAINTAIN PREGNANCY IN THE CASTRATED RABBIT

Abstract

Methylestronolone was capable of stimulating the activity of carbonic anhydrase in the rabbit endometrium, provided the hormone treatment (parenteral or oral) extended over a period of (at least) 5 days, but failed to induce a positive response when the treatment was limited to 2-3 days. The progestational action of methylestronolone was not of long duration, and was at its maximum within 5-20 hr after the cessation of treatment. The results concerning the degree of progestational development obtained by the "carbonic anhydrase test" were fully substantiated by the conventional bioassay method. Attempts to maintain pregnancy in ovariectomized rabbits with orally administered methylestronolone gave variable results, but in 2 instances live fetuses were recovered after a period of 8-10 days of treatment.