cAMP formation in HEK 293 cells stably transfected with h5-HT4aand h5-HT4b receptors
| Receptor (Clone) | h5-HT4a(8) | h5-HT4b (9) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| % 5-HTmax | pEC50 | n | % 5-HTmax | pEC50 | n | |||||
| Mean | ± S.D. | Mean | ± S.D. | Mean | ± S.D. | Mean | ± S.D. | |||
| 5-HT | 100 | 8.2 | 0.2 | 7 | 100 | 8.3 | 0.1 | 13 | ||
| 5-MeOT | 115 | 11 | 7.72-b | 0.1 | 6 | 111 | 3 | 8.3 | 0.2 | 6 |
| Cisapride | 982-b | 7 | 7.8 | 0.3 | 8 | 114 | 4 | 7.9 | 0.1 | 8 |
| Prucalopride | 118 | 7 | 8.22-b | 0.1 | 11 | 117 | 3 | 8.5 | 0.1 | 11 |
| SDZ-HTF919 | 114 | 15 | 8.72-a | 0.1 | 3 | 134 | 6 | 8.3 | 0.1 | 3 |
| Renzapride | 111 | 6 | 7.7 | 0.2 | 4 | 103 | 12 | 7.6 | 0.1 | 4 |
| SB204070 | 412-b | 3 | 9.52-a | 0.5 | 6 | 50 | 3 | 8.8 | 0.1 | 8 |
| SDZ205,557 | 31 | 7 | 7.6 | 0.2 | 3 | 30 | 11 | 7.5 | 0.1 | 3 |
The pEC50 values and percentage maximal responses were calculated by nonlinear regression analysis of each concentration-response curve. The maximal response of each compound was normalized to the maximal stimulation obtained with 5-HT (% 5-HTmax). Results are expressed as means (± S.D.) ofn independent experiments performed in duplicate.