Pituitary adenylate cyclase activating polypeptide is a potent vasodilator in humans

摘要: The vasodilator effect of the novel peptide pituitary adenylate cyclase activating polypeptide (PACAP) was investigated in humans. Forearm blood flow measured six healthy men by venous occlusion plethysmography. Infusion PACAP into brachial artery at 0.01, 0.1, 1, 3, and 10 pmol/min produced a dose-related increase forearm cannulated arm from 2.8 +/- 0.6 to 8.6 2.4 ml/100 ml/min highest dose (mean SEM, p less than 0.05). In subsequent experiment, where repeated after 36 min interval, there no tachyphylaxis response, with increasing 129 9% during first infusion 128 31% second (N.S.). further experiments, microvascular laser-Doppler probe compare effects intradermally injected PACAP, vasoactive intestinal (VIP), calcitonin gene-related (CGRP). When skin normal volunteers 10(-12) 10(-11) mol/site, each caused rapid flare lasting 2-3 min, which became erythematous 5 min. At VIP maximum 15 379 96 307 121% (% above basal SEM), respectively, these responses were not significantly affected oral aspirin (600 mg) taken 1.5 h beforehand. vasodilation induced mol/site lasted approximately 6 h, whereas same CGRP 2 h. These data suggest that is potent long-lasting