Table 2.
Potencies and maximal activities of tegaserod and motilin receptor agonists in rabbit isolated gastric antrum circular preparations
| Compound | Concentration (n) (μM) | Apparent pEC50 |
Maximum response |
|
|---|---|---|---|---|
| % increase | Concentration (μM) | |||
| r.motilin | 0.0001–0.3 (4–5) | 7.8±0.4 | 506±112 | 0.3 |
| [Nle13]motilin | 0.0003–0.3 (3–6) | 7.7±0.4 | 740±151 | 0.3 |
| Erythromycin | 0.1–10.0 (5) | 6.0±0.1 | 490±117 | 3.0 |
| Tegaserod | 0.01–10.0 (3–6) | 6.5±0.2 | 202±63 | 3.0 |
Abbreviations: EFS, electrical field stimulation; r.motilin, rabbit motilin.
Concentration–response curves to these ligands were derived by single applications of different concentrations to separate preparations of stomach, measuring their ability to facilitate cholinergically mediated contractions. Apparent pEC50 values are the concentrations which evoke a response which was 50% of the maximum increase in EFS-evoked contractions (maximum response).