Table 6.
SB-706375 is a competitive antagonist of hU-II-induced contraction of the rat isolated aorta
| Treatment | EC50 (nM) | Rmax (% 60 mM KCl) |
nH | Dose ratio |
|---|---|---|---|---|
| Vehicle | 2.3±0.4 | 97±10 | 1.90±0.15 | — |
| 0.3 μM SB-706375 | 24.0±7.7 | 122±9 | 1.93±0.20 | 13.1±3.5 |
| 1.0 μM SB-706375 | 79.3±15.1 | 122±7 | 1.97±0.19 | 47.6±9.2 |
| 3.0 μM SB-706375 | 182.6±43.4 | 114±8 | 1.68±0.18 | 166.2±66.3 |
SB-706375 (0.3–3.0 μM) caused concentration-dependent, parallel rightward shifts in the hU-II concentration–response curve. Values are expressed as mean±s.e.m. (n=12). Neither the maximum contractility (Rmax) nor Hill slope (nH) was altered by prior exposure to SB-706375 (parallel rightward shifts in the U-II concentration–response curve) as assessed by ANOVA (analysis for repeated measures; Dunnett's multiple comparisons post-test) consistent with surmountable, competitive mode of action in the rat isolated aorta.