Figure 3.

The effects of endothelial receptors antagonist on WGWP-induced vasorelaxation in rat aortic rings. We pretreated endothelial receptors antagonists, atropine (muscarinic receptor antagonist, 1.0 μM), diphenylhydramine (histamin receptor antagonist, 10 μM), propranolol (bradykinin receptor antagonist, 1.0 μM), and [D-Pro², D-Trp^7,9] substance P (substance P receptor antagonist, 5 μM), for 20 min and constricted rat aortic rings by 300 nM norepinephrine. Then, vasorelaxation was measured after treatment with WGWP 1.0 mg/mL. ^{A, B}Means with different letters are significantly different (P < 0.05) by one-way analysis of variance.