P450-dependent specific activities measured in rat OM and liver microsomes (mean ± standard deviation) Metabolites were separated by HPLC. Dextrorphan was detected by fluorimetry, with an excitation wavelength of 200 nm and an emission wavelength of 305 nm, and quantified by reference to a standard concentration. All other metabolites were quantified after on-line radiochemical detection using reference products. Statistical significance of differences was tested with Student's t test. n = number of experiments.
Substrate | Measured Metabolite | Specific Activity | Student's t Test (P <) | ||
|---|---|---|---|---|---|
| OM (n = 4) | Liver (n = 4) | ||||
| Phenacetin | Acetaminophen | 11,191 ± 1923 | 1431 ± 29 | 0.01 | |
| Chlorzoxazone | 6-OH-Chlorzoxazone | 10,070 ± 1722 | 3210 ± 415 | 0.01 | |
| Tolbutamide | OH-Tolbutamide | 8 ± 0 | 115 ± 17 | 0.01 | |
| Lauric acid | ω-OH-Lauric acid | 548 ± 73 | 473 ± 88 | N.S. | |
| Dextromethorphan | Dextrorphan | 2795 ± 173 | 2291 ± 203 | 0.01 | |
| Testosterone | 2α-OH-Testosterone | N.D. | 4500 ± 837 | ||
| 2β-OH-Testosterone | 2524 ± 291 | N.D. | |||
| 6α-OH-Testosterone | N.D. | N.D. | |||
| 6β-OH-Testosterone | 459 ± 67 | 1800 ± 231 | 0.01 | ||
| 7α-OH-Testosterone | N.D. | N.D. | |||
| 15α-OH-Testosterone | 3864 ± 482 | N.D. | |||
| 15β-OH-Testosterone | 2454 ± 239 | N.D. | |||
| 16α-OH-Testosterone | N.D. | 5560 ± 1066 | |||
| 16β-OH-Testosterone | N.D. | N.D. | |||
| Androstenedione | 608 ± 42 | 3600 ± 1208 | 0.01 | ||
|
| x | 1741 ± 226 | N.D. |
| |
N.D., not detectable; x, unidentified metabolite.