The effects of antagonists of vasoactive intestinal peptide on nonadrenergic noncholinergic inhibitory responses in feline airways.

Peptides1988PMID: 3131749

Plain Language Summary

Two VIP antagonists, including one based on a modified sermorelin structure, failed to effectively block VIP-induced or nerve-stimulated relaxation of feline airway smooth muscle. These results indicate that these particular antagonists are not reliable tools for studying VIP's role in airway nerve responses in cats, highlighting the need for more potent and specific VIP receptor blockers for respiratory research.

Abstract

Relaxations of the feline intrapulmonary bronchus (IPB) induced by VIP or nonadrenergic noncholinergic (NANC) inhibitory nervous stimulation were unaffected by the VIP receptor antagonist [Ac-Tyr1,D-Phe2]-GRF (1-29) (30 microM). A second VIP antagonist, [pCl-D-Phe6,Leu17]-VIP (30 microM), also had no effect on NANC relaxation responses or IPB sensitivity to VIP. However, responses to three of the four highest VIP concentrations were inhibited by this antagonist. These results indicate that [Ac-Tyr1,D-Phe2]-GRF (1-29) and [pCl-D-Phe6,Leu17]-VIP are not effective competitive antagonists of VIP receptors in feline airways and, hence, have but limited applicability in determining the role of VIP in mediating airway NANC inhibitory responses in this tissue.

Authors

Thompson, D C; Altiere, R J; Diamond, L