title: Participation of the CYP2D subfamily in lidocaine 3-hydroxylation and formation of a reactive metabolite covalently bound to liver microsomal protein in rats.
abstract: Lidocaine metabolism was investigated in rat liver microsomes and in a reconstituted system containing P450BTL, a cytochrome (P450) isozyme belonging to the CYP2D subfamily (Suzuki et al., Drug Metab Dispos 20: 367-373, 1992). P450BTL biotransformed lidocaine into 3-hydroxylidocaine (3-OH-LID) but not monoethylglycinexylidide and 2-methylhydroxylidocaine, in the reconstituted system including NADPH-P450 reductase and dilauroylphosphatidylcholine. An antibody against P450BTL inhibited microsomal lidocaine 3-hydroxylase activity by 97%. Thus, P450BTL and/or its immunorelated P450 isozyme(s) belonging to the CYP2D subfamily appear to be involved in lidocaine 3-hydroxylation. Furthermore, the antibody also suppressed the amounts of a lidocaine metabolite(s) bound to microsomal protein. These results suggest that the CYP2D subfamily biotransformed lidocaine into 3-OH-LID via an epoxy intermediate, which binds to microsomal macromolecules.
authors.affiliation: Laboratory of Biopharmaceutics, Faculty of Pharmaceutical Sciences, Chiba University, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Masubuchi
authors.forename: S
authors.initials: S
authors.lastname: Umeda
authors.forename: S
authors.initials: S
authors.lastname: Igarashi
authors.forename: S
authors.initials: S
authors.lastname: Fujita
authors.forename: S
authors.initials: S
authors.lastname: Narimatsu
authors.forename: T
authors.initials: T
authors.lastname: Suzuki
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000276:immunology; D001711:Biotransformation; D008012:Lidocaine / Q000031:analogs & derivatives* / Q000378:metabolism*; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology*; D008969:Molecular Sequence Data; D009247:NADH, NADPH Oxidoreductases / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000906:Antibodies; C075860:3-hydroxylidocaine; D008012:Lidocaine; D009247:NADH, NADPH Oxidoreductases; C069506:NADH-cytochrome P-450 reductase