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Titolo:
IDENTIFICATION OF MULTIPLE STEROID HYDROXYLASES IN DAPHNIA-MAGNA AND THEIR MODULATION BY XENOBIOTICS
Autore:
BALDWIN WS; LEBLANC GA;
Indirizzi:
N CAROLINA STATE UNIV,DEPT TOXICOL,BOX 7633 RALEIGH NC 27695 N CAROLINA STATE UNIV,DEPT TOXICOL,BOX 7633 RALEIGH NC 27695
Titolo Testata:
Environmental toxicology and chemistry
fascicolo: 7, volume: 13, anno: 1994,
pagine: 1013 - 1021
SICI:
0730-7268(1994)13:7<1013:IOMSHI>2.0.ZU;2-O
Fonte:
ISI
Lingua:
ENG
Soggetto:
RAT-LIVER; CYTOCHROME-P-450 ISOZYMES; HORMONAL-REGULATION; PIPERONYL BUTOXIDE; RAINBOW-TROUT; METABOLISM; ENZYMES; 3-METHYLCHOLANTHRENE; REGIOSELECTIVITY; HEPATOPANCREAS;
Keywords:
DAPHNIA; BIOMARKER; P450; TESTOSTERONE; METABOLISM;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
52
Recensione:
Indirizzi per estratti:
Citazione:
W.S. Baldwin e G.A. Leblanc, "IDENTIFICATION OF MULTIPLE STEROID HYDROXYLASES IN DAPHNIA-MAGNA AND THEIR MODULATION BY XENOBIOTICS", Environmental toxicology and chemistry, 13(7), 1994, pp. 1013-1021

Abstract

Steroid hydroxylase activities were characterized in Daphnia magna and evaluated for potential use as biomarkers of xenobiotic exposure. Microsomes prepared from Daphnia magna generated a single NADPH-dependent metabolite of [C-14]testosterone. However, intact daphnids excreted at least 10 polar metabolites of [ C]testosterone into the test medium. Six of these metabolites were identified as 2alpha-, 16beta-, 6beta-, 6alpha-, 7alpha-, and 15alpha-[C-14]hydroxytestosterone. The unidentified metabolites are also presumed to be hydroxylated products of testosterone, based on their relative migrations during TLC. The inefficient metabolism of [C-14]testosterone during the in vitro microsomal incubations may have been due to the release of P450 inhibitors during microsome preparation. Exposure of daphnids to the P450 modulators phenobarbital, beta-naphthoflavone, piperonyl butoxide, and malathion differentially inhibited the steroid hydroxylase activities. Results from this study indicate that Daphnia magna expresses several P450 enzymes and that these enzymes are differentially modulated by xenobiotic exposure. Steroid hydroxylase activities may serve not only as a biomarkerof toxicant exposure, but also as a predictor of toxicant effects involving perturbations of steroid hormone homeostasis.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 10/07/20 alle ore 02:34:49