Metabolism and excretion of 2-ethoxyethanol in the adult male rat.
Cheever-KL; Plotnick-HB; Richards-DE; Weigel-WW
Environ Health Perspect 1984 Aug; 57:241-248
The biotransformation of 2-ethoxyethanol (110805) was studied in the rat. The acute median lethal dose was determined by giving Sprague- Dawley-rats doses of 200, 500, 1000, 2000, 4000, and 8000 milligrams per kilogram (mg/kg) 2-ethoxyethanol by gavage. Similar rats were given a single oral dose of 250mg/kg 2-ethoxyethanol radiolabeled in the ethanol or ethoxy components. Expired air, urine and feces were collected. Radioactivity was determined by liquid scintillation counting. Urinary metabolites were identified by high performances liquid chromatography and gas and thin layer chromatography. The single oral dose median lethal dose was found to be 2300mg/kg. The principal route of elimination of administered radioactivity gas was through the kidney. About 75 to 85 percent of the dose was excreted in urine within 96 hours. Most of this occurred in the first 24 hours. Expiration accounted for 11.7 percent of the ethoxy labeled and 4.6 percent of the ethanol labeled compound. Relatively minor amounts were found in feces or remained in the carcass. Twelve distinct radiolabeled compounds were found to be urinary metabolites; 10 of these were found for either radiolabel. The two major urinary metabolites, 73 to 76 percent of the radioactivity administered, were identified as ethoxyacetic-acid (627032) and N- ethoxyacetyl-glycine. Ethoxyacetic-acid was the only radiolabeled compound in the testes. The authors conclude that metabolism of 2- ethoxyethanol in the rat proceeds primarily through oxidation to the corresponding acid. Reported testicular effects in the rat may result from tissue concentrations of ethoxyacetic-acid.
NIOSH-Author; Gas-chromatography; Quantitative-analysis; Analytical-chemistry; Analytical-methods; Laboratory-techniques; Biology; Chromatographic-analysis; Urinalysis; Laboratory-equipment; Animal-studies; Research
Environmental Health Perspectives