Activity of caffeine 13X, 17X, 37X, and 137U in genotyped dog and human liver microsomes
Caffeine (1 mM) was incubated for 30 min at 37°C with C/C, C/T, and T/T dog or human liver microsomes in the presence of NADPH. Each value represents mean ± S.D. of five dogs or the average of duplicate determinations. Values in parentheses represent the contribution of each pathway (%) to caffeine metabolism.
Species | 13X | 17X | 37X | 137U | Total | ||||
|---|---|---|---|---|---|---|---|---|---|
| nmol/min/mg protein | |||||||||
| Genotyped dog | |||||||||
| C/C | 0.041 ± 0.008 | 0.130 ± 0.033 | 0.047 ± 0.017 | 0.049 ± 0.014 | 0.267 ± 0.039 | ||||
| (15.4) | (48.7) | (17.6) | (18.4) | (100.0) | |||||
| C/T | 0.044 ± 0.007 | 0.149 ± 0.013 | 0.056 ± 0.005 | 0.041 ± 0.009 | 0.289 ± 0.033 | ||||
| T/T | 0.040 ± 0.008 | 0.147 ± 0.026 | 0.054 ± 0.009 | 0.034 ± 0.007 | 0.276 ± 0.045 | ||||
| Human | 0.006 | 0.097 | 0.019 | 0.005 | 0.127 | ||||
|
| (4.7) | (76.4) | (15.0) | (3.9) | (100.0) | ||||