TY - JOUR T1 - Metabolism-dependent inactivation of liver microsomal enzymes by phencyclidine. JF - Drug Metabolism and Disposition JO - Drug Metab Dispos SP - 371 LP - 375 VL - 12 IS - 3 AU - M K Hoag AU - A J Trevor AU - Y Asscher AU - J Weissman AU - N Castagnoli, Jr Y1 - 1984/05/01 UR - http://dmd.aspetjournals.org/content/12/3/371.abstract N2 - Incubation of phencyclidine (PCP) with rabbit liver microsomes resulted in NADPH-dependent loss of N-demethylase activity accompanied by reduction in microsomal cytochrome P-450 content. This effect was concentration-dependent, exhibited pseudo-first order kinetics, and was irreversible, thus exhibiting characteristics of "suicide substrate" inhibition. Cyanide ions at low concentrations, which have been used to trap the iminium intermediate of PCP metabolism as its cyano adduct, antagonized the inhibition of N-demethylase by PCP. PCP iminium ions were effective inhibitors of microsomal enzyme activity but required NADPH. These results support our suggestions that iminium ion formation is an intermediary step in the bioactivation of PCP leading to reactive electrophilic species. ER -