To determine the receptor localization and investigate the effect of U0126 treatment on ischemia-induced upregulation of smooth muscle vasoconstrictor receptor expression we performed immunofluorescence with antibodies against ETB (Fig. 5A-C) and 5-HT1B (Fig. 5D-F) receptors in MCAs from sham-operated rats and ischemia-induced rats treated with vehicle or U0126. Here, HTR1B is linked to ischemia.