(16-3H)progesterone metabolism in advanced pregnancy and in oophorectomized–hysterectomized women

Abstract

The introduction of paper chromatography and the availability of radio-iodide enabled Laidlaw (1949) to show that the circulating thyroid hormone was thyroxine and not thyroglobulin or a peptide, a conclusion supported by the work of Taurog, Chaikoff & Tong (1950) and Rosenberg (1951). After the discovery of tri-iodothyronine (Gross & Pitt- Rivers, 1952aRivers, , b, 1953a Roche, Lissitzky & Michel, 1952 a, b) it became clear that many of the earlier methods would not have been capable of differentiating between thyroxine and the new substance. The paper-chromatographic techniques * Part 1: Sprott & Maclagan (1955).

Isolation and Characterization of 5α-Pregnane-3, 20-dione and Progesterone in Peripheral Blood of Pregnant Women

“…With the exception of the initial phases of gestation, the human pla centa is recognized to be the major site of progesterone production [1], At term the placenta secretes at least 250 mg progesterone/day [19] and this is reflected in the urinary excretion of its major metabolites. However, relatively little is known of the mechanisms of action and total physiologic impact of this quantitatively important hormone of pregnancy.…”

The Metabolism of Corticosterone in Man

“…The same two techniques employed for cortisol turnover rates (18,25,27) ( 17,26,56,57), including cholesterol (58), have been used for tracer studies in human beings and in animals, and there is evidence that the H3 label is sufficiently stable. We have previously published data on the metabolism of simultaneous intravenously administered mixtures of corticosterone-4-C"4 and randomly labeled corticosterone-H3 (18).…”

“…The labeled corticosterone and its metabolites were presumed to be diluted only by the corresponding unlabeled steroid and its metabolites, and the collection of radioactivity in the metabolites was presumed to be nearly complete within the first 24 hours. From a knowledge of the specific activity of the isolated steroid and the quantity and specific activity of the injected steroid, plus a record of the time of the urine collection after administration of the labeled steroid, it was possible to calculate the rate of steroid secretion (17,18,26,27) I i -1) a X no. days = micrograms of steroid secreted per day, where It = specific activity of :njected steroid; f = ratio molecular weight of injected steroid to molecular weight of steroid metabolite; L. = specific activity of diluted urinary steroid metabolite; a = micrograms of steroid injected.…”

Conversion of plasma progesterone to deoxycorticosterone in men, nonpregnant and pregnant women, and adrenalectomized subjects.

“…During late human pregnancy, 250 mg or more of progesterone enter the maternal circulation each day (20,21). Thus, even a small fractional conversion of maternal plasma progesterone to DOC could account for considerable DOC production compared to that normally secreted by the adrenal cortex.…”