THE EFFECT OF HUMAN CALCITONIN-GENE-RELATED PEPTIDE ON EOSINOPHIL CHEMOTAXIS IN THE RAT AIRWAY

Eosinophils play a key role for the function of release inflammatory m ediators and destroy epithelial tissue in the airway. Therefore, they have been accepted to be proinflammatory effector cells in the pathoge nesis of the bronchial asthma. The aim of this study was to investigat e the effect of the calcitonin gene-related peptide (CGRP) a 37-amino acid neuropeptide on eosinophils responsible for hypersensitivity usin g BAL fluids that represent the cell population in the lung tissue. Fo r this purpose, 15 rats were divided into three groups receiving vehic le, 10(-6) M and 10(-5) M CGRP using a portable nebulizer. Nebulated e xposure of CGRP resulted in both significant increases in the eosinoph il numbers with 10(-6) and 10(-5) M CGRP of 18 +/- 0.913 cell/mm(2) (m ean +/- SEM; p < 0.01) and 31.25 +/- 1.931 (p < 0.01), respectively vs . control (12 +/- 0.408 cell/mm(2)). CGRP is capable of causing a eosi nophilia in the lung in vivo and may contribute to airway inflammation in patients with asthma.