Vehicle effect on concentration-response curves. A, Cumulative serotonin (5-hydroxytryptamine, 5-HT) concentration-response curve of basilar artery constriction normalized to 100 mM KCl induced-contraction, control arterial segments are compared to segments (n=5) incubated with 0.33% DMSO, 0.03% ethanol (ETOH) or both (n=6, for all vehicle groups), there are no statistical differences among curves. B, Cumulative endothelin-1 (ET-1) concentration-response curve of basilar artery constriction normalized to 100 mM KCl induced-contraction, control arterial segments (n=5) are compared to segments incubated with 0.33% DMSO, 0.03% ethanol (ETOH) or both (n=6, for all vehicle groups), there are no statistical differences among curves.