CGRP and ET-1 plasma levels in normal subjects.

Calcitonin gene-related peptide (CGRP) is a 37 amino acid peptide displaying about 50% homology with amylin which is secreted from the pancreatic islets of Langerhans. The main form, the beta-CGRP, is produced by the enteric nervous system and perivascular nerves of the vasa-vasorum. It represents one of the most powerful vasodilator yet discovered but its role is not yet completely clarified. High levels of this peptide have been shown in patients affected with thyroid medullary carcinoma, phaemocromocytoma and lung carcinoma. Recently circulating levels of CGRP have been found in normal subjects. Endothelin-1 (ET-1), a potent vasoconstrictor peptide, isolated from porcine endothelial cells, is an important regulator of the vascular tone acting in physiological antagonism with atrial natriuretic hormone (ANH). With this study we intended to investigate the presence of any correlation between CGRP and ET-1 in normal subjects.For the study we considered 20 normal subjects (11 males and 9 females) aged 23 to 50.Plasma levels of CGRP and ET-1 were measured by radioimmunological Kit.A positive and significant correlation between calcitonin gene-related peptide and endothelin-1 was found.Our results confirms that CGRP and ET-1 have opposing actions on vessels and that they can act together in haemodinamic regulation.