TABLE 2

Time-averaged free concentration ([I]u,ave) of MA in liver microsomes


Microsomal Protein

Nominal Concentration of MA

Percentage Freea

Time-Averaged Factorb

Time-Averaged Free Concentration ([I]u,ave) of MAc
μM μM
0.2 mg/ml 0.25 0.81 (0.10) 0.94 0.19
0.5 0.77 (0.08) 0.99 0.38
1 0.77 (0.09) 0.94 0.73
2 0.80 (0.08) 1.01 1.60
4 0.79 (0.07) 1.02 3.20
0.4 mg/ml 0.25 0.64 (0.04) 0.96 0.15
0.5 0.65 (0.04) 0.85 0.28
1 0.68 (0.08) 0.92 0.63
2 0.68 (0.08) 0.94 1.28
4 0.65 (0.08) 0.92 2.38
0.8 mg/ml 0.25 0.63 (0.01) 0.80 0.13
0.5 0.63 (0.04) 0.79 0.25
1 0.63 (0.03) 0.87 0.55
2 0.64 (0.02) 0.87 1.11

4
0.59 (0.04)
0.92
2.16
  • a Percentage free values are mean (SD), n = 3 incubations.

  • b Time-averaged factor (accounting for metabolic consumption) was calculated according to Materials and Methods.

  • c Nominal concentration multiplied by percentage free and time-averaged factor.