Polymorphic hydroxylation of perhexiline in vitro
- PMID: 12814462
- PMCID: PMC1884253
- DOI: 10.1046/j.1365-2125.2003.01805.x
Polymorphic hydroxylation of perhexiline in vitro
Abstract
Aims: The aims of this study were to examine the in vitro enzyme kinetics and CYP isoform selectivity of perhexiline monohydroxylation using human liver microsomes.
Methods: Conversion of rac-perhexiline to monohydroxyperhexiline by human liver microsomes was assessed using a high-performance liquid chromatography assay with precolumn derivatization to measure the formation rate of the product. Isoform selective inhibitors were used to define the CYP isoform profile of perhexiline monohydroxylation.
Results: The rate of perhexiline monohydroxylation with microsomes from 20 livers varied 50-fold. The activity in 18 phenotypic perhexiline extensive metabolizer (PEM) livers varied about five-fold. The apparent Km was 3.3 +/- 1.5 micro m, the Vmax was 9.1 +/- 3.1 pmol min-1 mg-1 microsomal protein and the in vitro intrinsic clearance (Vmax/Km) was 2.9 +/- 0.5 micro l min-1 mg-1 microsomal protein in the extensive metabolizer livers. The corresponding values in the poor metabolizer livers were: apparent Km 124 +/- 141 micro m; Vmax 1.4 +/- 0.6 pmol min-1 mg-1 microsomal protein; and intrinsic clearance 0.026 micro l min-1 mg-1 microsomal protein. Quinidine almost completely inhibited perhexiline monohydroxylation activity, but inhibitors selective for other CYP isoforms had little effect.
Conclusions: Perhexiline monohydroxylation is almost exclusively catalysed by CYP2D6 with activities being about 100-fold lower in CYP2D6 poor metabolizers than in extensive metabolizers. The in vitro data predict the in vivo saturable metabolism and pharmacogenetics of perhexiline.
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References
-
- Beaugrand M, Poupon R, Levy VG, Callard P, Lageron A, Lecomte D, et al. Hepatic lesions due to perhexiline maleate. Gastroenterol Clin Biol. 1978;2:579–588. - PubMed
-
- Pessayre D, Bichara M, Degott C, Potet F, Benhamou JP, Feldmann G. Perhexiline maleate-induced cirrhosis. Gastroenterology. 1979;76:170–177. - PubMed
-
- Hay DR, Gwynne JF. Cirrhosis of the liver following therapy with perhexiline maleate. NZ Med J. 1983;96:202–204. - PubMed
-
- Paliard P, Vitrey D, Fournier G, Belhadjali J, Patricot L, Berger F. Perhexiline maleate-induced hepatitis. Digestion. 1978;17:419–427. - PubMed
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