Table 2

Kinetic parameters for BG inhibition of phenacetin O-deethylation and DTIC N-demethylation

SubstratesEnzymeIC50m)Apparent Kim)Type of inhibition
PhenacetinCYP1A25.0 ± 1.71.1 ± 0.1Mixed
DTIC (1 mm)Microsomes2.8 ± 0.7
DTIC (150 μm)Microsomes1.5 ± 0.16
DTICCYP1A10.13 ± 0.020.19 ± 0.08Mixed
DTICCYP1A23.8 ± 1.11.3 ± 0.2Mixed