Studies on the metabolism and toxicity of dinitrotoluenes--on the absorption and excretion of tritium-labelled 2,4-dinitrotoluene (3H-2, 4-DNT) in the rat.

In order to investigate the detailed absorption and excretion of 2, 4-DNT in the rat, after the single oral administration of 3H2, 4-DNT, the time-course of radioactivity level in blood, liver and digestive organ contents, and of biliary, faecal and urinary excretion were observed. Radioactivity level in blood reaches a peak at 6 hr after the administration and its half-life was about 22 hr. Maximum level of radioactivity in the liver was observed at 6 hr after the administration as well as in the blood. In contrast with the radioactivity levels in blood and liver, amount of radioactivity in small intestine content is markedly decreased for 6 hr after administration. In the biliary excretion, about 10 per cent of the radioactivity administered was excreted in bile within 24 hr. The excretion rate is rising steadily from 6 hr after administration and its peak time was 9-10 hr. In the faecal excretion, the most of the excretion radioactivity was concentrated on 6-9 hr. In the faecal excretion, the most of the excretion radioactivity was concentrated on 6-9 hr faeces as reflected with the biliary excretion pattern. On the other hand, the most of the urinary excretion radioactivity was concentrated on 0-6 hr urine.