Comparison of affinities of the six inactivating drugs for the h5-HT7 receptor in radioligand binding assays with their potencies as insurmountable inhibitors of h5-HT7 receptor binding or inhibitors of h5-HT7 receptor activity
IC50 values are reported as the receptors are tested subsequent to the removal of the inactivating drug. Results are the means ± S.E.M. of three independent experiments performed in triplicate.
h5-HT7 Affinity (Membrane Homogenate Radioligand Binding) (Ki) | Insurmountable Inhibition (IC50) | |||
|---|---|---|---|---|
| Drug | h5-HT7 Whole-Cell Binding | h5-HT7-Receptor-Mediated cAMP Accumulation | ||
| nM | nM | |||
| Risperidone | 1.8 ± 0.3 | 9 ± 4 | 1.3 ± 0.5 | |
| 9-OH-Risperidone | 10 ± 1.7 | 5.5 ± 3.6 | 3.9 ± 2.1 | |
| Bromocryptine | 143 ± 56 | 152 ± 52 | 80 ± 22 | |
| Lisuride | 0.4 ± 0.2 | 3.0 ± 1.1 | 1.0 ± 0.3 | |
| Metergoline | 16 ± 2 | 73 ± 22 | 321 ± 130 | |
| Methiothepin | 3.0 ± 0.5 | 9.8 ± 1.3 | 3.0 ± 1.7 | |