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Titolo:
Urinary excretion of metabolites following a single dermal dose of [C-14]methyl parathion in pregnant rats
Autore:
Abu-Qare, AW; Abou-Donia, MB;
Indirizzi:
Duke Univ, Med Ctr, Dept Pharmacol & Canc Biol, Durham, NC 27710 USA Duke Univ Durham NC USA 27710 Pharmacol & Canc Biol, Durham, NC 27710 USA
Titolo Testata:
TOXICOLOGY
fascicolo: 1-3, volume: 150, anno: 2000,
pagine: 119 - 127
SICI:
0300-483X(20000907)150:1-3<119:UEOMFA>2.0.ZU;2-8
Fonte:
ISI
Lingua:
ENG
Soggetto:
METHYL-PARATHION; P-NITROPHENOL; ALKYL PHOSPHATES; METHYLPARATHION; FENITROTHION; EXPOSURE;
Keywords:
urinary excretion; kinetics; methyl parathion; p-nitrophenol; pregnant rats;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
28
Recensione:
Indirizzi per estratti:
Indirizzo: Abou-Donia, MB Duke Univ, Med Ctr, Dept Pharmacol & Canc Biol, POB 3813, Durham, NC 27710USA Duke Univ POB 3813 Durham NC USA 27710 Durham, NC 27710USA
Citazione:
A.W. Abu-Qare e M.B. Abou-Donia, "Urinary excretion of metabolites following a single dermal dose of [C-14]methyl parathion in pregnant rats", TOXICOLOGY, 150(1-3), 2000, pp. 119-127

Abstract

The identification and kinetics of urinary excretion of metabolites of uniformly phenyl-labeled O,O-dimethyl O-4-nitrophenyl phosphorothioate ([C-14]methyl parathion:) were carried out following a single dermal dose of 10.0 mg (10 mu Ci)/kg in pregnant Sprague-Dawley rats at 14-18 days of gestation. Urine was collected at each time interval of 1, 2, 4, 12, 24, 48, 72, and96 h after dosing. Total p-nitrophenol in the conjugated and non-conjugated metabolites was measured as a marker of methyl parathion exposure. Elimination of radioactivity in the urine was rapid. Of the total C-14 urinary excretion, 30% of the dose was excreted within 4 h, while 50 and 90% of the dose were recovered in the urine by 24 and 96 h, respectively. Excretion rate of total radioactivity was 60 mu g methyl parathion equivalent/h (1.4 mg/day). By the end of the 96-h experiment, conjugated and non-conjugated metabolites accounted for 78.1 and 21.9%, respectively. Of the non-conjugated metabolites, p-nitrophenol and O,O-dimethyl O-4-nitrophenyl phosphate (methyl paraoxon) were identified by high performance liquid chromatography (HPLC) that accounted for 20%, and 1.9% of total urinary excretion, respectively. Appearance and disappearance rate constants of p-nitrophenol in urine were 0.12 and 0.048 mu g/h, respectively. Conjugated metabolites were classified as: glucuronides 12% of urinary excretion, sulfates 3%, hot sulfuric acid hydrolysable residues 47% and 16.1% remained as unidentified water soluble metabolites. Direct hot acid hydrolysis of urine yielded 49% of extractable C-14-radioactivity compared to 62% when hot acid hydrolysis followed theenzymatic hydrolysis. The presence of the conjugated metabolites as the major class of metabolites of the total excretion indicates that determining only unbound p-nitrophenol as a biological marker for methyl parathion exposure underestimates total urinary excretion of p-nitrophenol. Sequential enzymatic and acid hydrolyses of urine prior solvent extraction are necessaryfor complete recovery of p-nitrophenol. The results indicate that the present method would show that the pregnant field worker or a housewife being at a greater risk than previously thought. (C) 2000 Elsevier Science IrelandLtd. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 05/07/20 alle ore 03:35:22