Dose-dependent metabolism of benzene in hamsters, rats, and mice.
The disposition of oral doses of [14C]benzene was investigated using a range of doses that included lower levels (0.02 and 0.1 mg/kg) than have been studied previously in rat, mouse, and in hamster, a species which has not been previously examined for its capacity to metabolize benzene. Saturation of metabolism of benzene was apparent as the dose increased, and a considerable percentage of the highest doses (100 mg/kg) was exhaled unchanged. Most of the remainder of the radioactivity was excreted as metabolites in urine, and significant metabolite-specific changes occurred as a function of dose and species. Phenyl sulfate was the predominant metabolite in rat urine at all dose levels (64-73% of urinary radioactivity), followed by prephenlmercapturic acid (10-11%). Phenyl sulfate (24-32%) and hydroquinone glucuronide (27-29%) were the predominant metabolites formed by mice. Mice produced considerably more muconic acid (15%), which is derived from the toxic metabolite muconaldehyde, than did rats (7%) at a dose of 0.1 mg/kg. Unlike both rats and mice, hydroquinone glucuronide (24-29%) and muconic acid (19-31%) were the primary urinary metabolites formed by hamsters. Two metabolites not previously detected in the urine of rats or mice after single doses, 1,2,4-trihydroxybenzene and catechol sulfate, were found in hamster urine. These data indicate the hamsters metabolize benzene to more highly oxidized, toxic products than do rats or mice.
Center for Bioorganic Chemistry, Research Triangle Institute, North Carolina 27709, USA.
J M
JM
Mathews
A S
AS
Etheridge
H B
HB
Matthews
D000818:Animals; D001554:Benzene / Q000008:administration & dosage / Q000493:pharmacokinetics*; D001711:Biotransformation; D002851:Chromatography, High Pressure Liquid; D006224:Cricetinae; D005243:Feces / Q000737:chemistry; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D051381:Rats; D011916:Rats, Inbred F344; D013045:Species Specificity; D013056:Spectrophotometry, Ultraviolet
D001554:Benzene