Concentration-response curves for ET-1 after ET_A (BQ-123), ET_B (BQ-788) or both receptors blockade on isolated rat basilar arteries following incubation with 5% CSF from <i>Non-Vasospasm</i> (panel A) and <i>Vasospasm</i> (panel B) patients.

<p>In the <b><i>Non-Vasospasm</i></b> group, the response to ET-1 was significantly reduced by the ET_A antagonist (n = 8), was not altered by the ET_B (n = 8) antagonist and greatly reduced by both antagonists (n = 5) compared to Vehicle (n = 8), whereas in the <b><i>Vasospasm</i></b> group, the increased sensitivity to ET-1 was significantly reduced by the ET_B (n = 9) antagonist in the low range, by the ET_A antagonist (n = 9) in the high range of ET-1 concentrations and was completely abolished by combined receptors blockade (n = 5) compared to Vehicle (n = 9). Significance at each concentration by a two-way ANOVA followed by a one-way ANOVA with Dunnett’s post-hoc analysis between groups, where *p<0.05 = ET_A antagonist versus vehicle, †p<0.05 = ET_B antagonist versus vehicle, #p<0.05 = ET_A and ET_B antagonists versus vehicle.