Fate of dipropyl sulphide and dipropyl sulphoxide in rat.

1. Dipropyl [35S]-sulphide and dipropyl [35S]-sulphoxide were administered by gavage (4.24 mM/4 ml/kg body wt) to adult male Wistar rats following an overnight fast. 2. Urine was the major route of excretion for both compounds, with more radioactivity appearing during the second day (c. 43%) than the first (c. 26%). Only small amounts were found in the faeces (c. 5%). Biliary excretion played an important role with substantial amounts of the dose (c. 25%) passing through the bile duct during 0-48 h. Following ingestion of the sulphide large quantities of radioactivity (18%) were detected in exhaled air. Near total recoveries were achieved for both compounds, although 13% of the radioactivity remained within the carcass 3 days after administration of the sulphoxide. 3. Absorption and elimination half-lives were in the region of 5 and 8 h, respectively, for both compounds, with the sulphoxide plasma profile showing a prolonged plateau region. 4. Metabolism was limited to oxidation of the sulphur with the formation of the sulphoxide and sulphone, and trace amounts of inorganic sulphate.