Hepatic microsomal metabolism of isoprene in various rodents.

Microsomal monooxygenases of various rodents metabolise isoprene to the corresponding monoepoxides, 3,4-epoxy-3-methyl-1-butene and 3,4-epoxy-2-methyl-1-butene. The kinetic constants (Km and Vmax) for the formation of the major products were determined by gas-liquid chromatography (GLC). The minor product was further epoxidised to the mutagenic isoprene dioxide by the microsomes of all rodents studied. The Km and Vmax for this subsequent epoxidation were determined and phenobarbital was found to be a good inducer in all species.