Ki values of 5-HT ligands for inhibition of [3H]GR 125743 binding to WT h5-HT1B, h5-HT1D, and the chimeric receptors D/B2ECL+V and B/D2ECL+V expressed in Cos-7 cells
| Ligand | WT h5-HT1B | B/D2ECL+V | D/B2ECL+V | WT h5-HT1D |
|---|---|---|---|---|
| L 694247 | 1.92 ± 0.05 | 1.20 ± 0.15b | 0.46 ± 0.16 | 1.08 ± 0.43 |
| Zolmitriptan | 20.58 ± 4.81 | 39.64 ± 9.32 | 1.19 ± 0.44 | 0.82 ± 0.21 |
| 5-HT | 46.18 ± 3.69 | 39.00 ± 9.54 | 5.22 ± 0.89 | 5.65 ± 0.66 |
| Sumatriptan | 78.79 ± 8.33 | 302 ± 59b | 5.26 ± 1.19 | 6.05 ± 2.08 |
| GR 127935 | 1.97 ± 0.11 | 0.96 ± 0.23 | 2.41 ± 0.91 | 4.85 ± 1.70 |
| SB 224289 | 6.70 ± 0.48 | 10.66 ± 3.46 | 116 ± 21 | 233 ± 71 |
| Ritanserin | 133 ± 25 | 22.37 ± 7.61a, d | 70.13 ± 23.57a, e | 16.85 ± 8.16 |
| Ketanserin | 2902 ± 422 | 115 ± 25c | 364 ± 56c | 24.02 ± 5.89 |
Radioligand binding was performed with 1.0 nm[3H]GR 125743 as described in the text. Results (K i, nm) are expressed as mean ± standard error values from three to six independent experiments, each one performed in duplicate.
Statistical analysis was performed using Student’s ttest: a p < 0.05,b p < 0.01, c p < 0.001 versus K i values of their respective WT receptors and d not significantly different compared with the WT h5-HT1D receptor, e not significantly different compared with the WT h5-HT1B receptor.