Suzanne H. Conrad

Inhibition of the Pregnenolone Δ5–3β-Hydroxysteroid Dehydrogenase-Δ5-4 Isomerase Systems of Human Placenta and Corpus Luteum of Pregnancy

The inhibition of the pregnenolone Δ 5–3Β-hydroxysteroid dehydrogenase-Δ5-4 isomerase systems in microsomes of human placenta or corpus luteum of

QUANTITATIVE PAPER CHROMATOGRAPHY OF CONJUGATED 17-KETOSTEROIDS IN PLASMA*

The determination of urinary 17-ketosteroids has limited applications in the understanding and diagnosis of the nature of endocrine disorders associated with mild hirsutism and virilism in the female, because a very large number of these patients excretes 17-ketosteroids well within the normal range. Recent experience of Finkelstein, Forchielli and Dorfman (1) suggests that in these cases the blood levels and nature of the circulating androgens may be very important. Earlier indirect evidence (2-12) and the more recent isolation and partial identification of sulfates of dehydroisoandrosterone, androsterone, and etiocholanolone by Baulieu (13) indicate that 17-ketosteroids are present in plasma mainly in the form of esters. Direct estimation of these conjugated steroids in plasma offers distinct advantages: the alteration of the steroid molecule which occurs with certain types of hydrolysis as well as possible problems of incomplete hydrolysis can be circumvented. Also, information concerning the physiological significance of the steroid conjugating mechanisms may be gained through direct qualitative and quantitative estimation of these conjugates. The present paper describes a convenient method, using quantitative paper chromatography, for the estimation of dehydroisoandrosterone and androsterone sulfates (DHIA-SO and Andro-SO4) in plasma.

Metabolism of progesterone by the term human placenta perfused in-situ

Abstract In situ perfusions using labelled progesterone as substrate were carried out in the human term placenta. Rapid metabolism was demonstrated. The major metabolites isolated in radiochemically pure form were 20α-hydroxypregn-4-en-3-one and 6β-hydroxypregn-4-ene-3,20-dione. Another metabolite was identified tentatively as 5β-pregnane-3,20-dione. No C-18 or C-19 steroids were found. Previous hypotheses have stressed the role of the fetus in the production of certain metabolites identified in umbilical cord blood. It is suggested that placenta I production be considered as well.

Utilization of precursor steroids in placental progesterone synthesis.

A number of radioactive steroid and sterol compounds were infused into the human term placenta in situ in an effort to assess their potential as precursors for progesterone production. Pregnenolone and pregnenolone sulfate were most efficiently converted to progesterone (12.8 and 12.9 per cent of injected radioactive material). 20β-dihydroprogesterone, 20β-dihydropregnenolone, and 20β-dihydropregnenolone-3-sulfate were converted in very low yield (

Perturbations of the human menstrual cycle by oxymetholone

The luteolytic activity of oxymetholone, and anabolic steroid, has been evaluated in 10 women. Administration early in the follicular phase of the cycle inhibited ovulation and prolonged the duration of the cycles in 2 of 3 subjects, but treatment beginning on Day 10 (3 subjects) did not prevent ovulation, although subsequent plasma progesterone concentrations were reduced. Treatment after ovulation (4 subjects) suppressed progesterone levels by 50 to 80 per cent and shortened cycle length by 6 to 8 days. Side effects were weight gain and bromosulfophthalein retention. The most likely mechanisms producing these perturbations are the inhibition of luteinizing hormone release early in the cycle and, later, inhibition of progesterone biosynthesis.