Function of 38 variants CYP2C9 polymorphism on ketamine metabolism in vitro

J Pharmacol Sci. 2017 Sep;135(1):8-13. doi: 10.1016/j.jphs.2017.08.006. Epub 2017 Sep 1.

Abstract

Background: Cytochrome P450 proteins (CYP 450) is the most important enzyme system of drug phase I metabolism in liver. In previous reports, reduced efficiency or increased risk of adverse events can be affected by primary sequence mutation in CYP450.

Aim: To investigate the effect of gene polymorphism on the metabolism of ketamine in vitro, including the new alleles: 2C9*58, *59 and *60.

Method: Incubation system which was contained insect microsome, b5, NADPH and 1M PBS incubated 10 μM-1000 μM ketamine in 37 °C for 40 min concentration of norketamine was analyzed by ultra-performance liquid chromatography-tandem mass spectrometry system (UPLC-MS/MS).

Result: Catalytic activity of thirty-eight CYP2C9 alleles on ketamine metabolism to norketamine was surveyed. Compared with 2C9*1, three alleles (2C9*40, *49 and *51) was demonstrated dramatically increased intrinsic clearance (1.2-fold-3.75-fold); four subtypes (2C9*27, *31, *41 and *56) exhibited no significantly change on enzyme activity. The resting 31 alleles expressed different degrees of reduction compared with wild type.

Conclusion: The result of research warns that attention should be more paid on individual who carry on the special 2C9 alleles under the situation of administrating ketamine.

Keywords: CYP2C9; Gene polymorphism; Intrinsic clearance; Ketamine; Metabolism.

MeSH terms

  • Animals
  • Cytochrome P-450 CYP2C9 / genetics*
  • Cytochrome P-450 CYP2C9 / physiology*
  • Ketamine / metabolism*
  • Pharmacogenomic Variants / genetics*
  • Pharmacogenomic Variants / physiology*
  • Polymorphism, Genetic / genetics*
  • Polymorphism, Genetic / physiology*
  • Sf9 Cells

Substances

  • Ketamine
  • Cytochrome P-450 CYP2C9