Neuropeptides concentrations in the skin of a murine (NC/Nga mice) model of atopic dermatitis

Background: It has been reported that the expression of neuropeptides (NPs), and the density and structure of peripheral nerves in atopic dermatitis (AD) are different from those in normal skin. Objective: We investigated the rote of NPs, in the development of AD with quantitative study of substance P (SP) and calcitonin gene-related peptide (CGRP) in the skin of AD-model mice. Methods: We measured the NPs in the skin of mice (NC/Nga as AD-model mice, BALB/c and C57BL/6 as control) by enzyme-linked immunosorbentassay (ELISA). Peripheral nerve fibers and SP in the skin were stained by immunohistochemical staining, using anti-PGP9.5 antibody and anti-SP antibody. Results: Under conventional condition, SP concentration in AD-like skin lesions of NC/Nga mice was higher than that in non-affected skin of the same mice. Under specific pathogen-free condition, SP concentration in the skin of NC/Nga mice was higher than that in the skin of BALB/c and C57BL/6 mice. In contrast, CGRP concentration in the skin lesions was lower than that in non-affected skin of NC/Nga mice. SP was detected not only in the nerve fibers in the dermis but also in mast cells in the inflammatory areas. Conclusions: The skin of NC/Nga mice contains more SP congenitally, and environmental factors may aggravate this abnormal condition. We hypothesize that increase of SP accompanied with a decrease of CGRP in the skin may play important roles in the pathogenesis and development of AD. (C) 2003 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.