Repeated subinflammatory ultraviolet B irradiation increases substance P and calcitonin gene-related peptide content and augments mustard oil-induced neurogenic inflammation in the skin of rats.
The cutaneous neurosensory system is suggested to be involved in the pathophysiology of pruritus and skin diseases such as psoriasis. We investigated if repeated subinflammatory doses of ultraviolet B (UVB) irradiation similar to those used to treat pruritus or psoriasis would affect the cutaneous neurosensory system. Sprague-Dawley rats were irradiated thrice weekly for 2-4 weeks with subinflammatory doses of UVB. Three days after the last UVB exposure: (i), the skin contents of substance P (SP), calcitonin gene-related peptide (CGRP), and nerve growth factor (NGF) were quantified; (ii), the skin nerve fiber density was observed; and (iii), the effect of UVB on mustard oil-induced neurogenic inflammation was determined. UV exposure significantly increased SP and CGRP content and mustard oil-induced neurogenic inflammation in UV-irradiated but not non-irradiated skin; however, it did not affect cutaneous NGF content or overall nerve fiber density. These data suggest that repeated subinflammatory UVB irradiation locally increases the content of cutaneous SP and CGRP by an increase of neuropeptide content of nerve fibers rather than by an increase of overall nerve fiber density.
Department of Dermatology, Karl-Franzens-University Graz Medical School, Auenbruggerplatz 8, 8036 Graz, Austria. franz.legat@uni-graz.at
Franz J
FJ
Legat
Thomas
T
Griesbacher
Rudolf
R
Schicho
Petra
P
Althuber
Rufina
R
Schuligoi
Helmut
H
Kerl
Peter
P
Wolf
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism*; D005260:Female; D009149:Mustard Plant; D009412:Nerve Fibers / Q000187:drug effects / Q000528:radiation effects; D020078:Neurogenic Inflammation / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D009475:Neurons, Afferent / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D010936:Plant Extracts; D010938:Plant Oils; D051381:Rats; D017207:Rats, Sprague-Dawley; D012867:Skin / Q000294:innervation* / Q000473:pathology / Q000528:radiation effects*; D013373:Substance P / Q000378:metabolism*; D014466:Ultraviolet Rays
D010936:Plant Extracts; D010938:Plant Oils; D013373:Substance P; D015740:Calcitonin Gene-Related Peptide; C027793:mustard oil