Vascular Effects of Neuropeptides on Nasal Mucosa

Abstract
We used dog nasal blood vessels and an in vitro muscle tension-detecting technique to examine the vascular effects of several neuropeptides: Vasoactive intestinal polypeptide, substance P, neurotensin, somatostatin, and neuropeptide Y (NPY). Electrically induced vasoconstriction was inhibited by every peptide except neurotensin, which enhanced this response. Every preparation treated with somatostatin, and one tissue treated with NPY, showed an enhanced noradrenaline-induced contraction. Only NPY caused a tissue contraction. Preparations precontracted by methoxamine were relaxed by every peptide. These results indicate that all peptides examined have marked but varied vasoactivities.