Effects of CYP inhibitors on EROD, MROD, and UROX activities catalyzed by microsomes from insect cells expressing human CYP1A1 and CYP1A2
| EROD3-a | MROD3-a | UROX3-b | |
|---|---|---|---|
| % | % | % | |
| CYP1A2 | 100 ± 1 | 100 ± 2 | 100 ± 2 |
| +Furafylline | 8 ± 1 | 15 ± 0 | 54 ± 3 |
| +αNF | 0 ± 0 | 0 ± 0 | 50 ± 4 |
| +Ketoconazole | 85 ± 0 | 86 ± 3 | 70 ± 14 |
| CYP1A1 | 100 ± 2 | 100 ± 1 | 100 ± 4 |
| +Furafylline | 45 ± 0 | 18 ± 1 | 99 ± 6 |
| +αNF | 0 ± 0 | 0 ± 0 | 153 ± 7 |
| +Ketoconazole | 4 ± 4 | 1 ± 1 | 81 ± 8 |
Values represent means and ranges of two to four determinations. Inhibitor concentrations were as follows: furafylline, 50 μM; α-naphthoflavone (αNF), 30 μM; ketoconazole, 50 μM.
↵3-a One hundred percent activities for EROD and MROD are presented in table 2.
↵3-b One hundred percent activities for UROX were 35 and 30 pmol of URO/min/nmol of CYP for CYP1A2 and CYP1A1, respectively, and were not corrected for activity present in microsomes from cells devoid of CYP.