Comparison of in vitro functional affinities of various endothelin receptor antagonists against contractions produced by S6c in the isolated rabbit pulmonary artery, or S6c-mediated dilation in the rabbit saphenous vein
| Compound | ETB1-mediated Dilation IC50(nM) | ETB2-mediated Constriction Kb(nM) |
|---|---|---|
| SB 234551 | 7000 | 555 ± 119 |
| SB 217242 | 70 | 353 ± 155 |
| SB 209670 | 4 | 16 ± 3 |
| Bosentan | 2000 | 1303 ± 1019 |
| BQ-788 | 300 | 1499 ± 1016 |
| RES 701 | 300 | >10,000 |
All compounds were evaluated at 10 μM; n = 4 to 5.