STUDIES ON THE METABOLISM OF C19 STEROIDS IN RAT LIVER. 6. HYDROXYLATION OF 4-ANDROSTENE-3,17-DIONE IN RAT LIVER MICROSOMES

1970 ◽  
Vol 65 (1) ◽  
pp. 84-94 ◽  
Author(s):  
Jan-Åke Gustafsson ◽  
Belisário P. Lisboa
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Rat Liver ◽  
Liver Microsomes ◽  
Gas Chromatography Mass Spectrometry ◽  
Male Rat ◽  
Rat Liver Microsomes ◽  
Relative Importance ◽  
Adult Male Rat ◽  
Layer Chromatography

ABSTRACT Following incubations of androstenedione with 105 000 × g microsomes of adult male rat liver, 6β-, 6α-, 7α-, 16α-, and 18-hydroxyandrostenedione were isolated by thin-layer chromatography and identified by gas chromatography-mass spectrometry. After incubations with testosterone the only 3,17-dioxo-Δ4-steroids formed were 6β- and 7α-hydroxyandrostenedione. 6β- and 18-Hydroxyandrostenedione were isolated after incubations with 6β- and 18-hydroxytestosterone, respectively. The relative importance of the 17-oxo- and the 17β-hydroxy-pathways in the formation of 3,17-dioxo-Δ4-C19O3 steroids is discussed.

Biosynthesis of 16α,17α-epoxy-4-androsten-3-one in rat liver microsomes

1980 ◽  
Vol 95 (1) ◽  
pp. 58-66 ◽  
Author(s):  
B. Disse ◽  
L. Siekmann ◽  
H. Breuer
Keyword(s):  
Rat Liver ◽  
Styrene Oxide ◽  
Liver Microsomes ◽  
Epoxy Compound ◽  
Male Rat ◽  
Gas Liquid Chromatography ◽  
Rat Liver Microsomes ◽  
Epoxide Hydratase ◽  
Layer Chromatography ◽  
Generating System

Abstract. 4,16-Androstadien-3-one was incubated with the microsomal fraction of male rat liver in the presence of a NADPH generating system and oxygen. The metabolites formed were extracted from the incubation medium and purified by thin-layer chromatography (tic). Final identification was performed by combined gas liquid chromatography-mass spectrometry. Incubation of 4,16-androstadien-3-one resulted in the formation of a non-polar metabolite which proved to be 16α,17α-epoxy-4-androsten-3-one. This epoxide is a shortlived intermediate which is rapidly hydrolysed by the microsomal epoxide hydratase to 16β,17α-dihydroxy-4-androsten-3-one. In order to increase the amounts of epoxide in the incubation mixtures, styrene oxide which is a potent inhibitor of the epoxide hydratase was added. Under these conditions, up to 8% of the 16-dehydro-steroid incubated was transferred to the 16α,17α-epoxy-compound.

scholarly journals Injury Elicited Increase in Spinal Cord Neurosteroid Content Analyzed by Gas Chromatography Mass Spectrometry

Endocrinology ◽  
2006 ◽  
Vol 147 (4) ◽  
pp. 1847-1859 ◽  
Author(s):  
F. Labombarda ◽  
A. Pianos ◽  
P. Liere ◽  
B. Eychenne ◽  
S. Gonzalez ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Spinal Cord ◽  
Gas Chromatography ◽  
Gas Chromatography Mass Spectrometry ◽  
Male Rat ◽  
Mrna Levels ◽  
Chromatography Mass Spectrometry ◽  
Chain Cleavage ◽  
Cord Injury ◽  
Adult Male Rat

The effects of spinal cord injury (SCI), combined with castration and adrenalectomy, and of progesterone (PROG) treatment on neurosteroid levels and steroidogenic enzyme expression were investigated in the adult male rat spinal cord (SC). Steroid levels were quantified by gas chromatography/mass spectrometry in SC and plasma, and mRNAs of enzymes by quantitative real-time RT-PCR. The levels of pregnenolone (PREG), PROG, 5α-dihydroprogesterone, 3α,5α-tetrahydroprogesterone increased in SC 75 h after transection without significant increase in the plasma. After combined adrenalectomy and gonadectomy, significant levels of PREG and PROG remained in the SC, suggesting their local biosynthesis. In the SC of adrenalectomized and gonadectomized rats, there was an increase of PREG 24 h after SCI, followed at 75 h by a concomitant increase in its direct metabolite, PROG. These observations are consistent with a sequential increase of PREG biosynthesis and its conversion to PROG within the SC in response to injury. However, no significant change in P450-side chain cleavage and 3β-hydroxysteroid dehydrogenase/Δ5-Δ4 isomerase mRNA levels was observed after SCI. Systemic PROG treatment after SCI, resulted in a very large increase in PROG, 5α-dihydroprogesterone, and 3α,5α-tetrahydroprogesterone in both plasma and SC. Furthermore, high levels of 3β,5α-tetrahydroprogesterone were detected in SC, whereas their plasma levels remained barely detectable. Because the ratio of reduced metabolites to PROG was 65-times higher in SC than in the plasma, it appears likely that reduced metabolites mainly originated from local biosynthesis. Our results strongly suggest an important role for locally biosynthesized neurosteroids in the response of the SC to injury.

scholarly journals Self-augmentation Effect of Male-specific Products on Sexually Differentiated Progesterone Metabolism in Adult Male Rat Liver Microsomes

2000 ◽  
Vol 276 (7) ◽  
pp. 4604-4610 ◽  
Author(s):  
Akihiko Yamada ◽  
Morio Yamada ◽  
Yukihisa Fujita ◽  
Takashi Nishigami ◽  
Keiji Nakasho ◽  
...  
Keyword(s):  
Rat Liver ◽  
Adult Male ◽  
Liver Microsomes ◽  
Male Rat ◽  
Rat Liver Microsomes ◽  
Progesterone Metabolism ◽  
Adult Male Rat ◽  
Male Specific

scholarly journals Progesterone-binding site of adult male rat liver microsomes.

1990 ◽  
Vol 265 (19) ◽  
pp. 11035-11043
Author(s):  
M Yamada ◽  
K Indo ◽  
T Nishigami ◽  
K Nakasho ◽  
H Miyaji
Keyword(s):  
Binding Site ◽  
Rat Liver ◽  
Adult Male ◽  
Liver Microsomes ◽  
Male Rat ◽  
Rat Liver Microsomes ◽  
Adult Male Rat

Relationship between Sigma-like site and progesterone-binding site of adult male rat liver microsomes

Hepatology ◽  
1994 ◽  
Vol 20 (5) ◽  
pp. 1271-1280 ◽  
Author(s):  
Morio Yamada ◽  
Takashi Nishigami ◽  
Keiji Nakasho ◽  
Yukiyasu Nishimoto ◽  
Hideki Miyaji
Keyword(s):  
Binding Site ◽  
Rat Liver ◽  
Adult Male ◽  
Liver Microsomes ◽  
Male Rat ◽  
Rat Liver Microsomes ◽  
Adult Male Rat
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