Related Experiment Video
Updated: Jul 10, 2026

Mass Spectrometry and Luminogenic-based Approaches to Characterize Phase I Metabolic Competency of In Vitro Cell Cultures
Published on: March 28, 2017
Gene-gene interactions between CYP2B6 and CYP2A6 in nicotine metabolism
Huijun Z Ring1, Ana M Valdes, Denise M Nishita
1Center for Health Sciences, SRI International, Menlo Park, CA, USA. huijun1@yahoo.com
Objectives:
CYP2A6 is the major enzyme involved in nicotine metabolism, yet large interindividual variations in the rate of nicotine metabolism exist within groups of individuals having the same CYP2A6 genotype. We investigated the influence of genetic variation in another potential nicotine-metabolizing enzyme, CYP2B6, and its interaction with CYP2A6, on the metabolism of nicotine.
Methods:
Two hundred and twelve healthy Caucasian adult twin volunteers underwent an intravenous infusion of stable isotope-labeled nicotine and its major metabolite, cotinine, for characterization of pharmacokinetic and metabolism phenotypes. Five CYP2B6 genetic polymorphisms causing amino acid substitutions (R22C, Q172 H, S259R, K262R, and R487C) were analyzed.
Results:
We observed that the CYP2B6*6 haplotype (defined as having both Q172 H and K262R variants) was associated with faster nicotine and cotinine clearance, and that such associations were more prominent among individuals having decreased-activity CYP2A6 genotypes. Statistically significant interactions between CYP2B6 and CYP2A6 genotypes were observed (P<0.003 for nicotine clearance and P<0.002 for cotinine clearance).
Conclusions:
Our results indicate that CYP2B6 genetic variation is associated with the metabolism of nicotine and cotinine among individuals with decreased CYP2A6 activity. Further investigation of the roles of CYP2B6 and the interaction between CYP2B6 and CYP2A6 genotypes in mediating nicotine dependence and tobacco-related diseases is merited.
More Related Videos
07:38A General Method for Detecting Nitrosamide Formation in the In Vitro Metabolism of Nitrosamines by Cytochrome P450s
Published on: September 25, 2017
09:50Impact Assessment of Repeated Exposure of Organotypic 3D Bronchial and Nasal Tissue Culture Models to Whole Cigarette Smoke
Published on: February 12, 2015
Related Concept Videos
Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes
Pharmacogenetics of Drug Metabolism: Overview
Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu
Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters