Decreases in ipsilateral cerebral blood flow (CBF) persist for 48 hours after intra-cortical injection of endothelin-1 (ET-1). CBF was quantitated in a 0.9 cm diameter circular region-of-interest centered on the injection site. Two-way ANOVA revealed a statistically significant effect of drug (F (1, 29) = 50.9, p < 0.001) and Bonferroni post-tests revealed a significant effect of ET-1 for both Wt and Tg mice (p < 0.05). No significant differences between Tg and Wt were detected. Inset Contralateral CBF was restored to control levels 48 hours after injection of either saline or ET-1. Data are means ± SEM, n = 12 Tg ET-1, 13 Wt ET-1, 4 Tg saline and 4 Wt saline.