Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1993-5-18
pubmed:abstractText
The in vitro metabolic activation of flutamide, a nitroaromatic antiandrogen which produces hepatitis in a few recipients, was first studied with male rat liver microsomes. There was no electron spin resonance evidence for the reduction of flutamide by reduced nicotinamide adenine dinucleotide phosphate (NADPH)-cytochrome P-450 reductase into a nitro anion free radical. In contrast, flutamide was oxidatively transformed by cytochrome P-450 into reactive metabolite(s) that covalently bound to microsomal proteins. Covalent binding required oxygen and NADPH, and was decreased by the nucleophile glutathione and by the cytochrome P-450 inhibitors SKF 525-A, piperonyl butoxide and troleandomycin (an inhibitor of the cytochrome P-450 3A subfamily). Covalent binding was increased markedly by pretreatment with dexamethasone (an inducer of the cytochrome P-450 3A subfamily) and moderately by pretreatment with beta-naphthoflavone (an inducer of the 1A family). Covalent binding was immunoinhibited markedly by anticytochrome P-450 3A immunoglobulin G and moderately by anticytochrome P-450 1A immunoglobulin G. Covalent binding was much lower with liver microsomes from female rats (not expressing P-450 3A2). Covalent binding of flutamide also occurred with human liver microsomes (where it was inhibited by troleandomycin), and with yeast microsomes expressing human liver cytochromes P-450 1A1, 1A2 or 3A4. We concluded that flutamide was oxidatively transformed into chemically reactive metabolite(s) by rat and human cytochromes P-450, including forms belonging to the 3A and 1A subfamilies.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0022-3565
pubmed:author
pubmed:issnType
Print
pubmed:volume
265
pubmed:owner
NLM
pubmed:authorsComplete
N
pubmed:pagination
366-72
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Metabolic activation of the nitroaromatic antiandrogen flutamide by rat and human cytochromes P-450, including forms belonging to the 3A and 1A subfamilies.
pubmed:affiliation
Institut National de la Santé et de la Recherche Medicale (INSERM) U-24, Hôpital Beaujon, Clichy, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't