Tissue distribution and excretion of 2,4-[14C]toluenediamine in the mouse.

The tissue distribution and excretion of 2,4-[14C]toluenediamine was studied in male mice given a single ip dose (1 microCi, 0.667 mg/kg). By 24 h 52% of the administered radioactivity had been excreted in the urine and 22% in the feces. The organs with the highest concentrations of radioactivity were the liver and kidneys. High concentrations of radioactivity were also observed in the gastrointestinal tract. Elimination of radioactivity from the liver, kidneys, and blood was biphasic, with half-lives of 11.7, 9.1, and 12.6 h, respectively, for the slow phases. The dominant route of excretion was via the kidneys; during the first hour after dosing, nearly 50% of the administered radioactivity was recovered in the urine. However, only an additional 2-4% of the dose appeared in the urine during the remaining 23 h of the experiment. By 24 h, only 1.25% of the administered radioactivity has been trapped from the air expired by the animals.