Effects of preimmune and anti-P450 antibodies on 5-FU formation catalyzed by human liver microsomes (samples HG3 and HG30)
| Antibody | HG3 | HG30 | |
|---|---|---|---|
| mg IgG/nmol P450 | nmol/min/nmol P450 | ||
| None | 0.42 (100) | 0.25 (100) | |
| Preimmune | 10 | 0.40 (96) | 0.24 (96) |
| Anti-CYP1A2 | 10 | 0.40 (96) | 0.20 (80) |
| Anti-CYP2A1 | 10 | 0.10 (24) | 0.15 (60) |
| Anti-CYP2A6 | 10 | 0.10 (24) | 0.15 (60) |
| Anti-CYP2C8 | 0.5 | 0.42 (100) | 0.13 (52) |
| Anti-CYP2C13 | 2.5 | 0.47 (114) | 0.12 (48) |
| Anti-CYP2E1 | 0.5 | 0.40 (96) | 0.26 (102) |
Tegafur (100 μM) was incubated with human liver microsomes (0.080 μM total P450) in the absence or presence of preimmune, polyclonal anti-rat CYP1A2, anti-rat CYP2A1, and anti-rat CYP2C13 antibodies and monoclonal anti-human CYP2A6, anti-human CYP2C8, and anti-human CYP2E1 antibodies. Results are presented as means of duplicate determinations. Values in parentheses indicate percentage of control activities.