Metabolism of iodomethane in the rat

Abstract

The LD50 of iodomethane orally administered to rats is 76 mg/kg body wt. but repeated daily doses of 30-50 mg/kg body wt. are without effect. Oral doses of iodomethane to rats are rapidly converted into S-methylglutathione in the liver, and S-methylglutathione is excreted in the bile. The conjugation process has been reproduced in vitro and shown to be enzymically catalysed. S-Methylglutathione is degraded to S-methylcysteine by kidney homo-genates. Only a small proportion of a dose of iodomethane or of S-methylcysteine is excreted as compounds related to methylmercapturic acid. Paper chromatography of extracts of livers from normal and dosed rats support the view that GSH is the predominant non-protein thiol present.