[Metabolism of 3-amino-1,2,4-triazole in rats]

3-Amino-1,2,4-triazole[5-(14)C] was administered orally to rats as a single dose of 50 mg/kg body weight. Excretion in urine and feces was followed during a period of 3 days. Within the first 24 hrs the main part of the radioactivity was found in the urine as unchanged amitrole. 3-Amino-5-mercapto-1,2,4-triazole and 3-amino-1,2,4-triazolyl-(5)-mercapturic acid were isolated from urine and identified by comparison with synthetic compounds. The total amount of these metabolites in the urine was about 6% of the dose. The metabolic pathways of amitrole and the possible relations between biotransformation and toxicity are discussed.