Summary. Rats were androgenized by injection of 50 μg testosterone propionate on the 5th day after birth and when adult were treated with 5 i.u. PMSG; some of the animals were mated. Serum was obtained daily and the concentrations of progesterone, 20α-dihydroprogesterone and prolactin, estimated by radioimmunoassays, were compared to values found for mated, but not ovulating, androgenized females and those for normal pregnant females.
Ovulation and luteinization of follicles occurred. The concentration of progesterone increased after the injection of PMSG and remained elevated for at least 10 days; mating did not alter the progesterone levels. The concentration of 20α-dihydroprogesterone was also elevated but the ratio of the level of progesterone to this steroid was generally greater than unity. Prolactin levels were elevated in the rats which ovulated. It is concluded that the corpora lutea induced in androgenized females by PMSG are functional and maintained.