Vasorelaxation effect of Pro C1 on 1.0 μM PE-constricted thoracic aortic rings in the presence of inhibitors. (A) 10 μM L-NMMA, (B) 10 mM TEA, and (C) 100 μM 2-APB were added before 1.0 μM PE constriction. Constricted tension was recorded after the addition of Pro C1. Results are expressed as mean±SEM (n=4). *P<.01 versus vehicle. 2-APB, 2-aminoethyl diphenylborinate; L-NMMA, NG-monomethyl-L-arginine; TEA, tetraethylammonium chloride.