TY - JOUR T1 - Metabolism of acrylonitrile to cyanide. In vitro studies. JF - Drug Metabolism and Disposition JO - Drug Metab Dispos SP - 376 LP - 379 VL - 8 IS - 6 AU - M E Abreu AU - A E Ahmed Y1 - 1980/11/01 UR - http://dmd.aspetjournals.org/content/8/6/376.abstract N2 - In liver fractions from Sprague-Dawley rats, the metabolism of acrylonitrile (VCN) to cyanide (CN-) was localized the microsomal fraction and required NADPH and O2 for maximal activity. The biotransformation of VCN to CN- was characterized with respect to time, microsomal protein concentration, pH, and temperature. Metabolism of VCN was increased in microsomes obtained from phenobarbital-, Aroclor 1254-, or 3-methylcholanthrene-treated rats (479%, 414%, and 142% of control, respectively) and decreased with CoCl2 treatment (54% of control). The KM estimated for VCN with the phenobarbital (54.8 +/- 9.5 mM) or Aroclor 1254 (40.9 +/- 4.1 mM) preparation was lower than the control (190.7 +/- 19.7 mM). Addition of SKF 525-A or CO to incubation mixtures inhibited VCN metabolism. Addition of the epoxide hydratase inhibitor, 1,1,1-trichloropropane 2,3-oxide, decreased the formation of CN- from VCN. Addition of glutathione, cysteine, D-penicillamine, or 2-mercaptoethanol enhanced the release of CN- from VCN. These findings indicate that VCN is metabolized to CN- via a cytochrome P-450-dependent mixed-function oxidase system. ER -