Neuropeptides in skin

The action of CGRP and SP on cultured skin fibroblasts

“…Usually, nerve endings deep in the dermis contain increased quantities of CGRP, SP, VIP and Neurokinin A (NKA), while those that penetrate the epidermis contain only SP, VIP and NKA [9,10]. The cutaneous concentration of neuropeptides changes according to the anatomic location.…”

“…The specific receptors, CGRP 1 and CGRP 2 receptors, coupled to the adenylate cyclase system bind to G-proteins [9]. CGRP is the most potent vasodilator known and its vasodilator effect on the skin (which is constant in the arterioles of all studied species) is caused by direct action on the muscle vascular bed.…”

“…CGRP acts intensively on sweat glands and perivascular nerves [9,18]. The specific receptors, CGRP 1 and CGRP 2 receptors, coupled to the adenylate cyclase system bind to G-proteins [9].…”

“…In addition, SP is chemotactic for T cells, enhances the proliferation and action of T and B cells, induces the expression of IL-1 and IL-6 by T cells, increases the production of immunoglobulins, the activity of natural killer cells and macrophages, and the production of IL-1 and IL-6 by T cells, TNF-alpha and prostaglandin E 2b (PGE 2b) mediated by NK-1R. However, unlike CGRP, SP induces human mast cell degranulation with release of histamine [9,28]. SP also induces proliferation of human dermal fibroblasts [30] and human and murine keratinocytes [31,32] and stimulates neovascularization in vivo and proliferation of endothelial and smooth muscle cells [9,28,33].…”

“…SP has a similar distribution to CGRP with respect to its targets. SP receptors, neurokinin (NK)-1R, NK-2R and NK-3R, coupled with a G-protein have been described in mast cells, polymorphonuclear leukocytes, monocytes, macrophages, thymus-derived (T) lymphocytes (or T cells), and bone marrow-derived (B) lymphocytes (or B cells) [9,28]. SP is one of the most potent vasodilators; it releases nitric oxide from endothelial cells.…”