Binding affinities for three different types of BZDs using wild-type and chimeric receptors
| Flunitrazepam | Ro15-1788 | Ro15-4513 | |||||
|---|---|---|---|---|---|---|---|
| KD | Bmax | n | KI | n | KI | n | |
| nm | pmol/mg | nm | nm | ||||
| α1β2γ2S | 9.9 ± 0.8 | 0.65 ± 0.07 | 16 | 4.3 ± 0.9 | 9 | 17.9 ± 4.9 | 9 |
| α1β2χ161 | 11.3 ± 1.7 | 0.34 ± 0.03 | 4 | 6.9 ± 1.2 | 5 | 25.5 ± 4.0 | 4 |
| α1β2χ167 | 13.3 ± 3.5 | 0.57 ± 0.17 | 3 | 6.4 ± 1.7 | 3 | 41.0 ± 11.2 | 3 |
The affinity of α1β2γ2S, α1β2χ161, and α1β2χ167 receptors for [3H]flunitrazepam (BZD agonist), Ro15-1788 (BZD antagonist), and Ro15-4513 (BZD inverse agonist) was measured by radioligand saturation and competition binding experiments. α1β2χ161 and α1β2χ167 receptors had an affinity similar to that of α1β2γ2S for all three types of BZD-site ligands tested. Results shown are mean ± standard error; n is the number of independent experiments.