title: The metabolism of 1,3-cyclohexadiene by liver microsomal mono-oxygenase.
abstract: 1. 1,3-Cyclohexadiene exhibits type I binding spectra with microsomal cytochrome P-450 of either untreated, or phenobarbital- or 3-methylcholanthrene-treated mice. In all cases, two values of Ks can be measured, indicating a different affinity of 1,3-cyclohexadiene towards the cytochrome P-450 species. 2. Mouse-liver microsomal mono-oxygenase metabolizes 1,3-cyclohexadiene to the corresponding mono-epoxide, which is rapidly hydrolysed to trans-3-cyclohexene-1,2-diol and trans-2-cyclohexene-1,4-diol. This hydrolysis was proved to be essentially nonenzymic. 3. A simple gas-chromatographic method was used to quantify the diols and to determine the kinetic constants (Km and Vmax) of 1,3-cyclohexadiene mono-epoxidase. 4. Epoxide formation, as determined by diol production from 1,3-cyclohexadiene metabolism, was NADPH- and O2-dependent and was inhibited by CO and SKF-525A.
mesh_terms: D000818:Animals; D002849:Chromatography, Gas; D003067:Coenzymes / Q000378:metabolism; D003510:Cyclohexanes / Q000378:metabolism*; D053138:Cyclohexenes; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D051379:Mice; D008862:Microsomes, Liver / Q000201:enzymology*; D009249:NADP / Q000378:metabolism; D010105:Oxygenases / Q000378:metabolism*
chemical_list: D003067:Coenzymes; D003510:Cyclohexanes; D053138:Cyclohexenes; D009249:NADP; D003577:Cytochrome P-450 Enzyme System; D010105:Oxygenases; C034005:1,3-cyclohexadiene