IDENTIFICATION OF STEROIDS PRODUCED BY BOVINE CHORION INCUBATED WITH [14C]ANDROSTENEDIONE

1981 ◽  
Vol 91 (3) ◽  
pp. 487-494 ◽  
Author(s):  
I. M. SIMONS ◽  
G. J. KING
Keyword(s):  
Early Pregnancy ◽  
Specific Activity ◽  
Separation And Purification ◽  
Short Term ◽  
Extraction Separation ◽  
Preliminary Extraction ◽  
Constant Specific Activity

Individual chorion taken from cows in early pregnancy (days 27, 44, 45 and 49) was incubated with [14C]androstenedione in short-term incubation in vitro. After preliminary extraction, separation and purification, metabolites were identified by recrystallization with authentic unlabelled steroids to constant specific activity. Major metabolites identified were 5β-androstane-3,17-dione (5β-androstanedione) and 5β-androstan-3α-ol-17-one (aetiocholanolone) while minor metabolites were identified as 5β-androstane-3α,17β-diol and 5β-androstan-17α-ol-3-one. There was no 14C-labelled oestradiol or oestrone detectable in the medium either as free oestrogens or as sulphates.

GLUCOCORTICOID SYNTHESIS FROM PREGNENOLONE BY SHEEP FOETAL ADRENALS IN VITRO

1973 ◽  
Vol 58 (3) ◽  
pp. 485-491 ◽  
Author(s):  
I. J. DAVIES ◽  
K. J. RYAN
Keyword(s):  
Isotope Dilution ◽  
Adrenal Glands ◽  
Specific Activity ◽  
Newborn Period ◽  
Adult Sheep ◽  
Age Related ◽  
Period Of Gestation ◽  
Constant Specific Activity

SUMMARY [7-3H]Pregnenolone was incubated with homogenates of adrenal glands from two 100-day-old sheep foetuses. Cortisol and corticosterone were isolated and identified by reverse isotope dilution and recrystallization to constant specific activity. Together these two compounds accounted for 12% and 17% of the substrate with the two tissue preparations. Other C21 and C19 metabolites which were sought were not present in appreciable quantities. Additional incubations were done with the adrenals of lamb foetuses ranging in age from 110 days of gestation to the immediate newborn period. Glucocorticoidogenic capacity similar to that of the 100-day-old foetuses was demonstrated throughout this period and no age-related change was evident. These results demonstrate that the lamb foetal adrenal has a substantial enzymic capacity for glucocorticoid synthesis throughout at least the last third of gestation. In conjunction with the observations of others, these experiments support the hypothesis that during this period of gestation the lamb foetal adrenal is actively synthesizing glucocorticoids in a manner which is similar to the lamb at term and the adult sheep.

FORMATION OF 17α-HYDROXY-PREGNENOLONE, 17α-HYDROXY-PROGESTERONE AND PROGESTERONE BY HYDATIDIFORM MOLES IN VITRO

1969 ◽  
Vol 61 (1) ◽  
pp. 68-75 ◽  
Author(s):  
Hubertus A. van Leusden ◽  
Maria Siemerink
Keyword(s):  
Urinary Excretion ◽  
Specific Activity ◽  
Full Term ◽  
Hydroxy Progesterone ◽  
Experimental Findings ◽  
Hydatidiform Moles ◽  
Constant Specific Activity

ABSTRACT Vesicles of hydatidiform moles were incubated in the presence of [7α-3H]pregnenolone, After the incubation and extraction of tissues and media, 17α-hydroxy-pregnenolone*, 17α-hydroxy-progesterone and progesterone were identified using a number of TLC systems, followed by crystallization to a constant specific activity. [7α-3H] pregnenolone was not converted to oestrone, 17β-oestradiol and oestriol. The experimental findings indicate that hydatidiform moles, like full term placentas, are deficient in the enzymes necessary to convert C21 to C19 steroids. The production of 17α-hydroxy-progesterone and progesterone in the molar trophoblast in situ may contribute to the considerable urinary excretion of pregnanetriol and pregnanediol in patients with hydatidiform moles.

THE CONVERSION OF PROGESTERONE TO 17α-HYDROXYPROGESTERONE BY HUMAN PLACENTA IN VITRO

1961 ◽  
Vol 36 (3) ◽  
pp. 455-461 ◽  
Author(s):  
Brian Little ◽  
Ann Shaw
Keyword(s):  
Human Placenta ◽  
Radiochemical Purity ◽  
Specific Activity ◽  
Fluid Fraction ◽  
Counter Current ◽  
Soluble Supernatant ◽  
Counter Current Distribution ◽  
Generating System ◽  
Constant Specific Activity

ABSTRACT The conversion of progesterone to 17α-hydroxyprogesterone by the soluble fraction of human placenta has been demonstrated in vitro. The incubation system contained the soluble supernatant fluid fraction of placental homogenate (105 000 × g), progesterone 4-14C as substrate, authentic 17α-hydroxyprogesterone as trap and a reduced triphosphopyridine nucleotide generating system as cofactor. The 17α-hydroxyprogesterone formed was isolated chromatographically and radiochemical purity was demonstrated by constant specific activity in a counter current distribution. Constant specific activity and radiochemical purity of the oxidation product and the acetylated derivative was also shown.

THE CONVERSION OF PREGNENOLONE TO PROGESTERONE AND 16α-HYDROXYDEHYDROEPIANDROSTERONE IN VITRO BY ADRENAL TISSUE FROM A NEWBORN ANENCEPHALIC INFANT

1968 ◽  
Vol 40 (1) ◽  
pp. 29-35 ◽  
Author(s):  
M. M. SHAHWAN ◽  
R. E. OAKEY ◽  
S. R. STITCH
Keyword(s):  
Specific Activity ◽  
Hydroxysteroid Dehydrogenase ◽  
Enzymatic Conversion ◽  
Partition Chromatography ◽  
Adrenal Tissue ◽  
Enzyme Systems ◽  
Constant Specific Activity

SUMMARY Adrenal tissue, largely composed of the definitive zone, from a newborn anencephalic infant, contained the following enzyme systems: (1) a Δ5-3β-hydroxysteroid dehydrogenase for pregnenolone, demonstrated by the conversion of [14C]pregnenolone to [14C]progesterone; (2) a C(17)-C(20) desmolase, and (3) a steroid 16α-hydroxylase, demonstrated by the conversion of [14C]pregnenolone to [14C]3β, 16α-dihydroxyandrost-5-en-17-one. The metabolites could not be separated from carrier steroids during sequential partition chromatography. [14C]Progesterone was identified by recrystallization to constant specific activity. [14C]3β, 16α-Dihydroxyandrost-5-en-17-one was identified by enzymatic conversion to [14C]16α-hydroxyoestrone followed by reduction to oestriol and determination of the specific activity of the oestriol after partition chromatography. It is suggested that these enzymes may play some part in the production of cortisol by the newborn anencephalic infant, and in the provision of precursors for placental oestriol production.

CORTICOSTEROID SYNTHESIS IN VITRO BY ADRENAL TISSUE FROM NEWBORN ANENCEPHALIC INFANTS

1969 ◽  
Vol 44 (4) ◽  
pp. 557-566 ◽  
Author(s):  
M. M. SHAHWAN ◽  
R. E. OAKEY ◽  
S. R. STITCH
Keyword(s):  
Newborn Infant ◽  
Specific Activity ◽  
Adrenal Tissue ◽  
Constant Specific Activity

SUMMARY Adrenal tissue from newborn anencephalic infants converted pregnenolone and progesterone to cortisol, 17α-hydroxyprogesterone, corticosterone, 17α,21-dihydroxyprogesterone, deoxycorticosterone and 1 1β-hydroxyprogesterone in vitro. These metabolites were identified by recrystallization to constant specific activity after multiple chromatography and derivative formation. The results demonstrate a potential for corticosteroid biosynthesis, at least from pregnenolone and progesterone, by the adrenals of the anencephalic infant, and therefore possibly by the definitive zone of the adrenal of the normal newborn infant.

METABOLISME DE LA TESTOSTERONE PAR LES CANAUX DE WOLFF DE L'EMBRYON DE RAT

1972 ◽  
Vol 70 (2) ◽  
pp. 351-359
Author(s):  
J.-P. Weniger ◽  
A. Zeis
Keyword(s):  
Specific Activity ◽  
Wolffian Duct ◽  
Rat Embryos ◽  
Duct Development ◽  
Constant Specific Activity

ABSTRACT Wolffian ducts from 17½-day-old rat embryos were cultivated in vitro in the presence of [4-14C] testosterone. The most important metabolite, if not the single one, was dihydrotestosterone, which was identified by recrystallization to constant specific activity. The discussion turns on the role dihydrotestosterone may play in normal Wolffian duct development. In parallel studies, testosterone was found to be converted into dihydrotestosterone, androsterone, androstanedione and 5α-androstan-3α,17β-diol by the kidney. Androsterone and androstanedione were metabolites of testosterone in the liver.

Stimulation of aromatase activity in the fetal rat gonads by cAMP and FSH

1988 ◽  
Vol 119 (3) ◽  
pp. 381-385 ◽  
Author(s):  
J.-P. Weniger ◽  
A. Zeis
Keyword(s):  
Specific Activity ◽  
Isotopic Dilution ◽  
Aromatase Activity ◽  
Fetal Rat ◽  
Estrogen Synthesis ◽  
Fetal Rats ◽  
Stimulation Of ◽  
Constant Specific Activity

Abstract. The gonads from 17- to 21-day-old fetal rats were cultured in vitro in the presence of [3H]testosterone and in the presence or absence of cAMP or FSH, and estrone and estradiol formed were measured by double isotopic dilution and recrystallization to constant specific activity. Estrogen synthesis by testes was stimulated by both cAMP and FSH as early as at 18 days of gestation. FSH did not enhance aromatase activity in ovaries, although cAMP did. It is remarkable that FSH controls estrogen synthesis in the testis earlier than in the ovary.

PATHWAYS IN THE BIOSYNTHESIS OF ANDROGENS IN THE POSTMENOPAUSAL OVARY IN VITRO

1971 ◽  
Vol 66 (2) ◽  
pp. 325-332 ◽  
Author(s):  
J. G. Schenker ◽  
W. Z. Polishuk ◽  
B. Eckstein
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Specific Activity ◽  
Ovarian Tissue ◽  
Tissue Homogenates ◽  
Layer Chromatography ◽  
Constant Specific Activity

ABSTRACT Postmenopausal ovarian tissue homogenates were incubated with [7α-3H]-pregnenolone as substrate. In six independent incubations only androstenedione and testosterone were found. These androgens were isolated by column and thin-layer chromatography and identified by derivative formation and recrystallization to constant specific activity. In one of the incubations, the homogenate was divided into 3 parts. From one part incubated with [7α-3H] pregnenolone, androstenedione and testosterone were identified. From the second and third parts of the homogenate which were incubated with [4-14C]progesterone and [4-14C] testosterone respectively, the substrates were recovered unmetabolized at the end of the incubation. From these results it is deduced that the postmenopausal ovary can not aromatize androgens to oestrogens and that in this particular tissue the Δ5 pathway is the preferred route of androstenedione production.

CONVERSION OF PREGNENOLONE TO PROGESTERONE BY RABBIT PLACENTA IN VITRO

1969 ◽  
Vol 61 (4) ◽  
pp. 577-584 ◽  
Author(s):  
K. Matsumoto ◽  
G. Yamane ◽  
H. Endo ◽  
K. Kotoh ◽  
K. Okano
Keyword(s):  
Isotope Dilution ◽  
Specific Activity ◽  
Enzyme System ◽  
Hydroxysteroid Dehydrogenase ◽  
Pregnant Rabbit ◽  
Dehydrogenase Enzyme ◽  
Constant Specific Activity

ABSTRACT A placental preparation from rabbits in mid-pregnancy was shown to convert 7α-3H-pregnenolone to radioactive progesterone in vitro. The extent of conversion per gram tissue by the placenta was about one hundredth of that by the ovary from the pregnant rabbit. Identification of radioactive progesterone was accomplished by reverse isotope dilution and recrystallization to constant specific activity. However, no Δ5-3β-hydroxysteroid dehydrogenase was found histochemically in the trophoblast and other tissues of the rabbit placenta. No ability to convert 7α-3H-pregnenolone to radioactive 20α-hydroxypregn-4-en-3-one, 20β-hydroxypregn-4-en-3-one, corticosterone, cortisol, androst-4-ene-3,17-dione, dehydroepiandrosterone, 17β-oestradiol and oestrone in placental preparation from rabbits could be demonstrated. The data demonstrate the presence of a 3β-ol-dehydrogenase enzyme system in the rabbit placenta.

IDENTIFICATION DES CORTICOSTEROIDES SECRETES PAR LES SURRENALES EMBRYONNAIRES DE VEAU, LAPIN ET SOURIS CULTIVEES IN VITRO

1970 ◽  
Vol 65 (4) ◽  
pp. 650-662 ◽  
Author(s):  
J. Chouraqui ◽  
J.-P. Weniger
Keyword(s):  
Thin Layer ◽  
Mouse Embryo ◽  
Sodium Acetate ◽  
Specific Activity ◽  
Mouse Embryos ◽  
Rabbit Embryo ◽  
Constant Specific Activity

ABSTRACT Adrenals from calf, rabbit and mouse embryos were incubated with [1-14C] sodium acetate. The corticosteroids were extracted from the incubation media and identified by sequential thin-layer radiochromatography and derivative formation, either alone or combined with recrystallization to constant specific activity. It is concluded that adrenals from calf embryo synthesize in vitro cortisol, corticosterone and 11-dehydrocorticosterone; from rabbit embryo, cortisone, cortisol and aldosterone; and from mouse embryo, cortisol, corticosterone, 11-dehydrocorticosterone, 11-deoxycorticosterone and aldosterone.

Sign in / Sign up

Export Citation Format

Share Document