Differences In Progesterone Concentrations Research Articles

Evaluation of progesterone synthesis in rabbit placentas.

The contribution of the rabbit placenta to maternal plasma progesterone was investigated by ovariectomizing 21-day pregnant does and maintaining pregnancy for 3 days by Depo-Provera® treatment. Following ovariectomy, maternal plasma progesterone levels decreased to nonpregnant values within 24 hr and remained low, indicating that the placentas do not contribute a detectable amount to plasma progesterone. Sham ovariectomized rabbits, whether on Depo-Provera® treatment or not, showed no significant difference in progesterone concentrations in comparison to unoperated, untreated controls, suggesting the lack of a feedback control exerted by Depo-Provera over progesterone production in nonovariectomized pregnant does. (Endocrinology 94: 925, 1974)

Steroid hormone concentrations in blood plasma from residents of Zambia, belonging to different ethnical groups.

ABSTRACT Using competitive protein binding assays, the concentrations of progesterone, oestradiol, testosterone and cortisol have been measured in blood plasma from groups of men and women living in Zambia, but having European, African or Asian origins. All subjects were in apparent good health. For the women, blood was taken in both follicular and luteal phases of the menstrual cycles. In a separate study, the diurnal variation in cortisol was examined. Oestradiol concentration was higher in blood from African men than from men of the other two groups. Asian women showed the lowest luteal phase plasma oestrogen level. African men had lower mean testosterone in plasma than the other groups, while African women had higher results. There were no ethnic differences in progesterone concentrations. Plasma cortisol was significantly higher in African subjects of both sexes than for the other groups, while the diurnal variation in plasma cortisol was much reduced in the Africans.