Metabolism and excretion of 2,4-dinitrotoluene in male and female Fischer 344 rats after different doses.

Female Fischer 344 rats are less susceptible to the hepatocarcinogenic effects of 2,4-dinitrotoluene (2,4-DNT) than males. This study is a comparison of the metabolism and excretion of 2,4-DNT in male and female rats after oral doses of 10, 35, or 100 mg of 14C-2,4-DNT per kg. The major route of elimination of 14C after all doses was the urine. 4-(N-Acetyl)amino-2-nitrobenzoic acid (4Ac2NBAcid), 2,4-dinitrobenzoic acid (2,4-DNMBAcid), 2-amino-4-nitrobenzoic acid (2A4NBAcid), and 2,4-dinitrobenzyl alcohol glucuronide (2,4-DNBAlcG) were identified in urine of rats. These four compounds accounted for greater than 85% of the radioactivity excreted in urine. Female rats excreted a significantly greater percentage of the dose in the urine as 2,4-DNBAlcG at doses of 10 or 35 mg/kg when compared to males. Both sexes showed dose-dependent changes in urinary excretion of 2,4-DNT metabolites. Males excreted a smaller percentage of the dose as 2,4-DNBAcid at 100 mg/kg than at 10 or 35 mg/kg. Females excreted less of the dose as 2,4-DNBAcid and 2,4-DNBAlcG at 100 mg/kg than at 10 or 35 mg/kg. The only sex difference in 2,4-DNT metabolism or excretion of sufficient magnitude to account for the sex difference in susceptibility to the hepatocarcinogenic effects of 2,4-DNT was the greater percentage of 2,4-DNT excreted as 2,4-DNBAlcG by female rats at 10 or 35 mg/kg.