title: Distribution, metabolism, and excretion of musk xylene in rats.
abstract: Distribution, metabolism and excretion of musk xylene (MX) were investigated in male Wistar rats. Urinary and fecal excretion accounted for 10 and 75% of the dose (70 mg/kg), respectively, on day 7 after orally administration of 3H-MX to rats. Total residue of radioactivity in tissues on day 7 was less than 2.0% of the administered dose. The highest concentration was found in adipose tissue and the second was in liver. Some metabolites of MX were identified using GC-MS and NMR after purification by column or thin layer chromatography of feces, bile and urine extracts. MX, 2-NH2-MX, 2-Ac-MX, 2-NH2-3-CH2OH-MX, and 2-NH2-5-tert-BuOH-MX were found in feces, bile and urine. 4-NH2-MX and metabolite X were found in feces and urine. 4-NH2-3-CH2OH-MX was found in urine. HO-MX was found in bile. The major route of excretion for MX was the feces via bile. The reduction of the 2-nitro group of MX to the amino group was a key step in metabolism. Further metabolism of 2-NH2-MX may proceed by decreased steric hindrance of functional group.
authors.affiliation: Division of Xenobiotic Metabolism and Disposition, National Institute of Hygienic Sciences, Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Minegishi
authors.forename: S
authors.initials: S
authors.lastname: Nambaru
authors.forename: M
authors.initials: M
authors.lastname: Fukuoka
authors.forename: A
authors.initials: A
authors.lastname: Tanaka
authors.forename: T
authors.initials: T
authors.lastname: Nishimaki-Mogami
mesh_terms: D000818:Animals; D002855:Chromatography, Thin Layer; D005243:Feces / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D014018:Tissue Distribution; D014316:Tritium; D014992:Xylenes / Q000378:metabolism* / Q000493:pharmacokinetics / Q000652:urine
chemical_list: D014992:Xylenes; D014316:Tritium; C031447:musk xylene