Plasma neuropeptide pattern in acute idiopathic urticaria.

Immediate hypersensitivity responses, as acute urticaria, produce a release of neuropeptides by nerve endings, which present specificity of recognition by mast cells, basophils and other target cells. We have measured vasoactive intestinal peptide (VIP), somatostatin, bombesin, neurotensin and beta-endorphin by radioimmunoassay in plasma extracts of 20 patients with acute idiopathic urticaria and of 20 healthy subjects. VIP- and beta-endorphin-like immunoreactivities were found to be significantly decreased with respect to controls (p less than 0.001 and p less than 0.01, respectively). On the contrary, somatostatin- and bombesin-like immunoreactivities were significantly increased (p less than 0.001 and p less than 0.05, respectively). These findings could be a reflection in blood of a raised release of somatostatin and bombesin by nerve endings in the urticaria process. Moreover, the decreased plasma levels of VIP- and beta-endorphin-like immunoreactivities could be explained by a raised specific metabolism of these peptides in the urticaria process.