Rats were treated with 50 mg/kg capsaicin on the second day of life or at the age of two-three months. Inflammatory reactions were brought about three-four and one-two months after capsaicin pretreatment, respectively. The fibre composition and fibre size spectra of saphenous nerves were also determined. Neurogenic inflammation was produced either by antidromic electrical stimulation of the saphenous nerve or by mustard oil in the skin of the rat paw. The permeability increasing effect of histamine, serotonin and bradykinin was tested on the abdominal skin. Neonatal capsaicin treatment resulted in a marked reduction of the neurogenic inflammatory response, and parallel with this there was a 60-70% reduction in the number of unmyelinated (C) fibres of the saphenous nerve. There was also a significant reduction in the vascular permeability increasing effect of histamine, serotonin and bradykinin in rats treated as neonates with capsaicin, but not in those treated in the adult age. It is concluded that chemosensitive pain fibres by the release of a neurogenic permeability increasing factor, most probably substance P, may effectively modulate the acute inflammatory reactions. Furthermore, it seems likely that substances of neuronal origin may contribute to the protective mechanisms of the organism and to the maintenance of the normal function of the skin.
|Number of pages||10|
|Journal||International Journal of Tissue Reactions|
|Publication status||Published - Jan 1 1980|
ASJC Scopus subject areas
- Immunology and Allergy
- Cell Biology