CGRP-immunoreactive nerves in prurigo nodularis--an exploration of neurogenic inflammation.
BACKGROUND
The present study has explored the localization and distribution of calcitonin gene-related peptide (CGRP)-immunoreactive (IR) nerve fibers in prurigo nodularis, especially emphasizing its relationships to mast cells and eosinophils, which all are important contributors to inflammation.


METHODS
The exact localization of CGRP in the nerve fibers of prurigo nodularis lesional skin has been clarified by an ultrastructural immunogold labelling technique; and the relationships of CGRP-IR nerve fibers to tryptase-IR mast cells or eosinophil cationic protein (ECP)-IR eosinophils were also investigated by immunofluorescence double-labelling.


RESULTS
This ultrastructural study has demonstrated that CGRP immunoreactivity is increased in the dense-core vesicles in the axons of the prurigo nodularis lesional skin; the axons which contain CGRP are, in addition, enlarged and have more dense-core vesicles than the axons which do not contain CGRP. The immunofluorescence investigation demonstrated that tryptase-containing mast cells and ECP-containing eosinophils also are significantly increased in the lesional skin.


CONCLUSIONS
The results indicate that certain neurons increasingly express CGRP, which may dynamically result in a neurogenic inflammation in the lesional skin, through vasodilatation, and recruitment and regulation of inflammatory cells, e.g. eosinophils and mast cells.
Liang
Y
Y
Department of Neuroscience, Karolinska Institute, Stockholm, Sweden.
Jacobi
H H
HH
Reimert
C M
CM
Haak-Frendscho
M
M
Marcusson
J A
JA
Johansson
O
O
D000368:Aged; D000369:Aged, 80 and over; D000906:Antibodies; D001369:Axons / Q000737:chemistry / Q000473:pathology / Q000648:ultrastructure; D001706:Biopsy; D001798:Blood Proteins / Q000032:analysis; D015740:Calcitonin Gene-Related Peptide / Q000032:analysis* / Q000276:immunology; D053818:Chymases; D047091:Eosinophil Granule Proteins; D004804:Eosinophils / Q000737:chemistry / Q000276:immunology; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D008297:Male; D008407:Mast Cells / Q000201:enzymology / Q000276:immunology; D016253:Microscopy, Immunoelectron; D008875:Middle Aged; D009443:Neuritis / Q000276:immunology / Q000473:pathology*; D010525:Peripheral Nerves / Q000737:chemistry* / Q000473:pathology*; D011536:Prurigo / Q000473:pathology*; D012260:Ribonucleases; D012697:Serine Endopeptidases / Q000032:analysis; D053802:Tryptases
D000906:Antibodies; D001798:Blood Proteins; D047091:Eosinophil Granule Proteins; D012260:Ribonucleases; D012697:Serine Endopeptidases; C083294:chymase 2; D053818:Chymases; D053802:Tryptases; D015740:Calcitonin Gene-Related Peptide