Document Detail

Cholesterol side-chain cleavage activity in human placenta and bovine adrenals: an one-step method for separation of pregnenolone formed in vitro.
MedLine Citation:
PMID:  6549417     Owner:  NLM     Status:  MEDLINE    
Cholesterol side-chain cleavage (CSCC) activity towards exogenous cholesterol was quantified by an one-step reversed-phase minicolumn method for the separation of pregnenolone formed in the reaction. The assay is rapid and reproducible. The method is linear for up to 2 mg of placental mitochondrial protein and up to 1 mg of bovine adrenal mitochondrial protein in the incubata over 30 min and 5 min reaction times, respectively. Average Km and Vmax values were 14.1 microM and 3.4 pmol/min/mg for the placental preparation and 1.5 microM and 20.7 pmol/min/mg for the bovine adrenal mitochondrial preparation. In human placenta, the mitochondrial fraction contained most of the CSCC activity. Inhibition studies showed that aminoglutethimide (500 microM) inhibited both placental and bovine adrenal activities at the same level (about 80-90% inhibition) but androstenedione (500 microM), metyrapone (500 microM), benzo(a)pyrene (800 microM) and Emulgen 911 (0.05%) were more effective in human placental preparations. Neither of the activities were inhibited to any great extent by alpha-naphthoflavone (500 microM), SKF 525A (500 microM) or 7-ethoxycoumarin (1 mM).
M Pasanen; O Pelkonen
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Publication Detail:
Type:  In Vitro; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Steroids     Volume:  43     ISSN:  0039-128X     ISO Abbreviation:  Steroids     Publication Date:  1984 May 
Date Detail:
Created Date:  1985-05-16     Completed Date:  1985-05-16     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0404536     Medline TA:  Steroids     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  517-27     Citation Subset:  IM    
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MeSH Terms
Adrenal Glands / enzymology*
Cholesterol / analysis,  metabolism*
Cholesterol Side-Chain Cleavage Enzyme / analysis,  metabolism*
Chromatography, Thin Layer
Oxidoreductases / metabolism*
Placenta / enzymology*
Pregnenolone / analysis,  biosynthesis*,  isolation & purification
Progesterone / analysis
Reg. No./Substance:
145-13-1/Pregnenolone; 57-83-0/Progesterone; 57-88-5/Cholesterol; EC 1.-/Oxidoreductases; EC Side-Chain Cleavage Enzyme

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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