PHYSIOLOGY OF THE CORPUS LUTEUM

Abstract

Experiments indicate that active progestin-containing extracts lose their ability to produce progestational proliferation in the castrated rabbit''s uterus when they are given simultaneously with sufficient amounts of oestrin; 675 r.u. [rabbit units] of oestrin inhibit completely 3 r.u. of progestin. Large doses of oestrin (1000 r.u.) given during the 1st 5 days after mating prevent the development of proliferation but do not prevent the development of normal appearing corpora lutea. Large doses of oestrin (1000 r.u.) given during the 2d 5 days after mating cause extensive endometrial degeneration with sloughing of the endometrium, but produced no demonstrable changes in the corpora lutea. The placentae start to form but are very abnormal.