A, B, Topical application of the ET_A receptor antagonist BQ123 (1 μm) partially reverses the attenuation of CBF responses to whisker stimulation (A) and ACh (B) induced by AngII infusion for 14 d. The effect is not enhanced by pretreatment with SR49059 (in drinking water, days 7–14 of AngII infusion) (*p < 0.05 from respective saline group; ^#p < 0.05 from Ringer's and respective saline groups; n = 5 per group). C, D, Neocortical application of losartan (5 μm) partially reverses the attenuation of CBF responses to whisker stimulation (C) and acetylcholine (D) induced by AngII infusion for 14 d (*p < 0.05 from saline; ^#p < 0.05 from vehicle and saline; n = 5 per group). E, F, Losartan completely reverses the cerebrovascular dysfunction induced by acute AngII administration, attesting to its effectiveness (*p < 0.05 from saline; n = 5 per group). G, H, Topical application of BQ123 + losartan completely reverses the cerebrovascular dysfunction (*p < 0.05 from respective saline group; ^#p < 0.05 from Ringer's, BQ + Los and respective saline groups; n = 5 per group).