Ovulation in prenatally androgenized ewes

Abstract

The ovarian activity of prenatally androgenized ewes was studied by measuring plasma progesterone concentrations in daily samples of peripheral blood, and by examining the ovaries at laparotomy. Ewes that were exposed to testosterone between days 30 and 80, 50 and 100 or 70 and 120 of foetal life by implanting their mothers with 1 g testosterone, failed to show regular overt oestrous cycles, although some of them ovulated, whereas ewes exposed to testosterone between days 90 and 140 of foetal life had normal oestrous cycles. The incidence of ovulatory failure appeared to increase with age in ewes treated between days 50 and 100 or days 70 and 120 of foetal life.

PIP: The effect of prenatal androgenization of ovulation in ewes was investigated by measurement of plasma progesterone concentrations and examination of the ovaries at laparotomy. The animals were exposed to testosterone by implantation of their mothers with 1 gm testosterone between Days 30-80, 50-100, 70-120, or 90-140 of fetal life. Ewes exposed during the first 3 periods to testosterone failed to show regular, overt estrous cycles, though ovulation did occur in some cases. Animals exposed between Days 90-140 of fetal life had normal estrous cycles. There appeared to be an age-related increase in the incidence of ovulatory failure in ewes exposed between Days 50-100 or Days 70-120 of fetal life.