[The effect of concomitant administration of dehydroepiandrosterone with progesterone on decidual growth in the rat (author's transl)].

Studies were made on the effect of concomitant administration of dehydroepiandrosterone acetate (DHA-Ac) with progesterone on decidual growth in the rat. Virgin female rats of Wistar strain weighing about 250 g were used. Daily vaginal smears were recorded and, during the time of vaginal cornification, the animals were made pseudopregnant by tapping the uterine cervix. Day 1 of the pseudopregnancy was designated as the day that the vaginal smears contained primarily leucocytes. On day 4 of the pseudopregnancy, each animal was laparotomized midventrally, and bilateral ovariectomy and scratching of the uterine endometrium were performed. Progesterone, alone or in combination with DHA-Ac, was injected from day 4 of the pseudopregnancy (immediately after ovariectomy) through day 8. On day 9 of the pseudopregnancy all animals were killed. The weights of the uterus, and the deciduoma-inducing score, etc, were estimated. Massive deciduomata weighing 2768 +/- 84 mg per uterus were induced in intact pseudopregnant rats. Treatment with 2 mg progesterone evoked maximal responses of only 754 +/- 101 mg. The concomitant administration of 20 mg DHA-Ac with 2 mg progesterone reproduced the decidual weight observed in intact rats, but 2.5 mg or 5 mg DHA-Ac in combination with 2 mg progesterone was only slightly effective. The weights of the uterus, the deciduoma-inducing score, the histological findings, and the effects of the DHA-Ac were discussed.