Affinity values (n = 3, average ± S.D.) of histamine ligands for the human H3 receptor on GPCR105
| Compound | GPCR105 ReceptorKI | H3 Receptor KI |
|---|---|---|
| nM | ||
| Imetit | 2.7 ± 0.6 | 0.3 ± 0.2 |
| Histamine | 8.1 ± 3.2 | 5.4 ± 4.4 |
| Immepip | 9.0 ± 1.0 | 0.4 ± 0.1 |
| Impromidine | 12.3 ± 4.0 | 67 ± 16 |
| Clobenpropit | 12.8 ± 3.0 | 0.6 ± 0.2 |
| N-Methylhistamine | 23 ± 30 | 0.5 ± 0.4 |
| Thioperamide | 27 ± 13 | 25 ± 7.4 |
| R-α-methylhistamine | 146 ± 68 | 0.7 ± 0.3 |
| Burimamide | 180 ± 40 | 84 ± 20 |
| Dimaprit | 377 ± 170 | 825 ± 535 |
| Clozapine | 510 ± 110 | >10,000 |
| Ranitidine | >10,000 | >10,000 |
| Cimetidine | >10,000 | >10,000 |
| Cyproheptadine | >10,000 | >10,000 |
| 4-(3-Piperidin-1-yl-propoxy)-benzonitrile | >10,000 | 25 ± 10 |
| Diphenhydramine | >10,000 | >10,000 |
K I values for the GPCR105 receptor were determined by competition binding of 3H-histamine. K Ivalues for the histamine H3 receptor were determined by competition binding of 3H-R-α-methylhistamine.