Steroid hormones and the metabolism of oxygen by the uterus of pregnant sheep after ovariectomy.

Abstract

Effects of ovariectomy on maternal hormones, on uterine blood flow, and on 02 metabolism of sheep late in gestation were studied. Ovariectomy was associated with lower concentrations of estrone, estradiol, and progestagens in femoral arterial and uterine venous blood and with less variation in the concentration of estrogens, variation which normally is related to day of pregnancy. Birth weight, neonatal weight-gain, and rates of both uterine blood flow and 02 consumption apparently were unaffected, but statistically significant differences were observed in the arterial 02 content and in the fraction of 02 extracted by the uterus. Histologic examination of ovaries during the last half of gestation revealed follicles developing and at least one healthy corpus luteum in every pair of ovaries. This evidence suggests that the ovaries are active, that they contribute to maternal hormonal concentrations, and that they havea measureableeffect on patterns of 02