Parameters used in the simulation of mechanism-based inhibition
Substrate | Inhibitor |
Dose = 2 μmol | Dose = 5000 μmol |
Fa = 0.8 | Fa = 0.8 |
fb = 0.1 | fb = 0.2 |
ka = 0.01 min−1 | ka = 0.02 min−1 |
Km = 100 μM | Km = 10 μM |
Vmax(0) = 200 μmol/min | Vmax(0) = 30 μmol/min |
Vd = 70 L | Vd = 20 L |
Kp = 1 | Kp = 1 |
Enzyme | Physiological parameters |
kdeg = 0.0005 min−1 | Q = 1610 mL/min |
Ki,app = 20 μM | Vh = 2800 mL |
kinact = 0.06 min−1 | Vportal = 70 mL |
E0 = 5 nmol P450/g liver |
Q, blood flow rate; Csys and Isys, concentration in systemic blood; Vd, volume of distribution in the central compartment; Cportal and Iportal, concentration in portal vein; Vportal, volume of portal vein; Ch and Ih, concentration in liver; Vh, volume of liver; fb, unbound fraction in blood; CLint, intrinsic metabolic clearance; Fa, fraction absorbed from the intestinal tract; Km, Michaelis constant for the metabolic elimination; Vmax, Maximum metabolic rate for the metabolic elimination; Kp, liver-to-blood concentration ratio.