TABLE 3

Comparison of relative reaction rates with literature data Reaction velocities are expressed relative to that of naloxone (relative activity = 100). The concentration of compounds in microsomal incubations was 1 mM except for propofol (0.5 mM) and 17α-ethynylestradiol (0.25 mM).


Compound

Relative Activity in HLM

DLM/HLM Activity Ratioa
HPLC Methodb
SPE Methodc
Ratio SPE/HPLC
HPLC Methodb
SPE Methodc
Furosemide 24 35 1.5 6.4 2.7
17α-Ethynylestradiol 28 43 1.5 7.4 N.D.
Naproxen 52 57 1.1 8.9 5.8
Propofol 58 93 1.6 N.D. N.D.
Valproic acid 62 43 0.7 6.5 8.3
Naloxone 100 100 1.0 15.4 3.9
Gembfibrozil 182 136 0.7 10.0 5.8
Hyodeoxycholic acid 1422 207 0.15 0.3 1.0
Naphtol
2015
1929
1.0
10.6
4.5
  • N.D., not determined.

  • a Ratio of reaction velocity in dog vs. human liver microsomes

  • b Radiometric HPLC method. Velocities at the drug concentration used were calculated from the Vmax and Km values given in Soars et al. (2001b)

  • c Radiometric SPE method (present work). Velocities are given in Table 2