Human calcitonin gene‐related peptide activates adenylate cyclase and releases prostacyclin from human umbilical vein endothelial cells

1 Endothelial cells of human umbilical vein were isolated and cultured in vitro. 2 In these cells there was a concentration‐dependent release of prostacyclin and activation of adenylate cyclase by human calcitonin gene‐related peptide (hCGRP). The concentration of hCGRP for half‐maximum activation of adenylate cyclase (Kact) by hCGRP was 190 nm. 3 Bradykinin induced a ten fold greater release of prostacyclin than CGRP, but did not activate adenylate cyclase. 4 hCGRP may exert its potent vasodilator properties by stimulating release of vasorelaxant substances, including prostacyclin from endothelial cells.