Table 1

Kinetic parameters of azelastine N-demethylase activity in human liver microsomes

No.KM1Vmax1Vmax1/KM1KM2Vmax2Vmax2/KM2
μM pmol/min/mg μl/min/mg μM pmol/min/mg μl/min/mg
HL 12.412.35.187.0115.11.3
HL 21.610.16.386.5196.62.3
HL 34.33.30.860.6245.44.0
HL 41.427.219.484.7201.52.4
Mean ± S.D.2.4 ± 1.313.2 ± 10.17.9 ± 8.079.7 ± 12.8178.9 ± 54.32.5 ± 1.1

Azelastine (1–200 μM) was incubated for 30 min with 0.5 mg/ml of human liver microsomes.