Effect of enzyme substrates on radioligand binding to MAO-B in human liver membrane preparations
| Enzyme substrate | Binding site | |
|---|---|---|
| [3H]Ro 196327 | [3H]Idazoxan | |
| Ki(μ m) | ||
| Phenylethylamine | 11.7 ± 0.9 | 23.9 ± 0.7 |
| Dopamine | 218 ± 6.1 | 127 ± 26 |
| Tyramine | 293 ± 28 | 47.7 ± 12 |
| Serotonin | >2 mM | 257 ± 7.3 |
[3H]Ro 19-6327 (30 nm) and [3H]idazoxan (10 nm) binding were performed using 30 mg and 100 mg of human liver membrane protein, respectively. Results are expressed as the mean ± standard deviation of two experiments.