TABLE 2

CYP2A6 phenotypes at different levels (n = 90)

Relative phenotypes, R-Vmax, R-CL, R-Content, referring to relative Vmax, CL, and Content, respectively, were computed to make CYP2A6 phenotypes at different levels comparable. Each level’s relative Vmax, CL, and Content (R-Vmax, R-CL, and R-Content) were calculated as the individual Vmax, CL, and Content divided by the median of corresponding parameter for that level. Molecular level, or phenotype at the protein level, Vmax-P (pmol/min per picomole), CL-P (μl/min per picomole). Subcellular level, or phenotype at microsomal level, Vmax-M (pmol/min per milligram), CL-M (μl/min per milligram), Content-M (pmol/mg). Tissue level, or phenotype at liver tissue level, Vmax-LT (pmol/min per gram), CL-LT (μl/min per gram), Content-LT (pmol/g). Organ level, or phenotype at liver level, Vmax-L(nmol/min per kilogram), CL-L (μl/min per kilogram), Content-L (nmol/kg). Organism level, or phenotype (clearance) at in vivo level, CL-H (ml/min).

LevelVmaxCLContent
RangeRatioR-VmaxRangeRatioR-CLRangeRatioR-Content
Molecular (protein)M 19.7963.81.16 ± 0.718.7352.91.19 ± 0.86—–—–—–
R 1.08–68.890.83–43.89—–
Subcellular (microsomal)M 354.41511.07 ± 0.78144.84540.97 ± 0.4314.6038.11.22 ± 0.75
R 9.47–14301.20–544.71.44–54.89
Tissue (liver tissue)M 12.272471.28 ± 1.145.192841.12 ± 0.68637.642.61.09 ± 0.56
R 0.25–61.740.06–17.0371.17–3031
Organ (liver)M 2672142.08 ± 1.86a,b,c109.22731.13 ± 0.70893.294.11.14 ± 0.89
R 6.22–13371.36–371.258.43–5497
Organism (in vivo)M—–—–—–287.31691.05 ± 0.48—–—–—–
R—–3.87–653.5—–
  • M, median; R, range.

  • a P < 0.05 vs. Vmax-P at molecular level.

  • b P < 0.05 vs. Vmax-M at microsomal level.

  • c P < 0.05 vs. Vmax-LT at tissue level.