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Lidocaine metabolism in human liver microsomes by cytochrome P450IIIA4
Author(s) -
Bargetzi Mario J,
Aoyama Toshifumi,
Gonzalez Frank J,
Meyer Urs A
Publication year - 1989
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1038/clpt.1989.180
Subject(s) - microsome , isozyme , cytochrome p450 , metabolite , lidocaine , biochemistry , metabolism , enzyme , drug metabolism , chemistry , cirrhosis , antiserum , cytochrome , pharmacology , biology , medicine , antibody , immunology , neuroscience
The metabolism of lidocaine to its major metabolite monoethylglycinexylidide (MEGX) was studied in human liver microsomes of 13 kidney transplant donors and of one patient with liver cirrhosis. Interindividual variation in metabolite formation was considerable. Biphasic kinetics indicated the involvement of at least two distinct enzymatic activities. With use of a series of antisera that recognize different human cytochrome P450 isozymes, we were able to identify an enzyme of the P450III gene family as one of two enzymes. By expressing human P450IIIA4 complementary deoxyribonucleic acid (cDNA) in HepG2 cells, we directly demonstrated lidocaine‐deethylase activity for this P450 isozyme. These data suggest that P450IIIA4 is at least in part responsible for microsomal MEGX formation. Clinical Pharmacology and Therapeutics (1989) 46, 521–527; doi: 10.1038/clpt.1989.180