Vasoactive intestinal polypeptide promotes cyclic adenosine 3',5'-monophosphate accumulation in guinea-pig trachea

Cyclic adenosine 3',5'-monophosphage (cyclic AMP) levels in guinea-pig tracheal rings increased on incubation with the vasoactive intestinal peptide (VIP). The effect was potentiated by the addition of theophylline. The results suggest that the tracheo-bronchial relaxant action of VIP may be mediated by stimulation of tracheal adenylyl cyclase.