The Involvement of Mast Cells in Vasodilatation Due to Axon Reflexes in Injured Skin

Abstract

Immediately subjacent to a scratch damaging the epidermis of the external ear of the albino rat, all the dermal mast cells are degranulated. The Although mast cells occur in peripheral nerves [Olsson, 1968] and, in some mammals, in the central nervous system [Campbell and Kiernan, 1966; Kruger, 1970], no report has been found in the literature indicating whether these cells are subject to any form of nervous control. Electron microscopic studies in the central nervous system [Flood and Kruger, 1970 Wiedmann, 1958;Stach, 1961].Since mast cells contain histamine and other vasoactive substances [see Selye, 1965], and since both sensory and sympathetic nerves are concerned with vasomotor control in the skin, the following investigation was undertaken. The area of skin studied, that of the external ear, was chesen because, in the rat, most of the skin of the auricle is supplied by a single, easily accessible, nerve trunk [Greene, 1935]. MATERIALS AND METHODSThe experimental animals were sixty adult albino Wistar rats of both sexes. For all operations and acute experiments the rats were anaesthetized with pentobarbitone sodium (3 0 mg/kg body weight, intraperitoneally). Denervation. In seventeen rats, a segment, 5 mm long, was removed from the common trunk of the great auricular and lesser occipital nerves on one side, and the nerve allowed to degenerate for 3 weeks.Sympathectomy. In eleven rats, the superior and middle cervical sympathetic ganglia were removed unilaterally. The trunk of the vagus nerve was also severed, as there is some evidence [Navaratnam, Lewis and Shute, 1968, p. 230] that this may

Role of peptidoleukotrienes in capsaicin‐sensitive sensory fibre‐mediated responses in guinea‐pig airways.

“…The airway mast cell must be considered as a candidate since mast cells are known to synthesize peptidoleukotrienes, and substance P has been found to stimulate certain types of mast cells as monitored by histamine release (Fewtrell et al 1982;Devillier et al 1985). Furthermore, mast cells have long been implicated in contributing to capsaicin-sensitive neuronal responses in the skin (Kiernan, 1971(Kiernan, , 1972(Kiernan, , 1975. However, neither EFS, capsaicin, or substance P evokes measurable quantities of histamine release from the guinea-pig trachea or bronchus (Undem, Adams & Buckner, 1989).…”

Modification by Capsaicin and Compound 48/80 of Dye Leakage Induced by Irritants in the Rat

“…A neurogenic component of the inflammatory response has been previously demonstrated for capsaicin (Jancso et al, 1967) and formalin (Brown, Kissel & Lish, 1968 humour' is liberated on stimulation of sensory nerves. Kiernan (1972a) Kiernan, 1972b;prostaglandin E1-Crunkhorn & Willis, 1971 (Moncada, Ferreira & Vane, 1973;Williams & Morley, 1973) and it is possible that the combination of bradykinin and prostaglandin E, produced so much more stimulation of the sensory nerves than either bradykinin or prostaglandin E1 alone, and also enhancement of the effects of the amines released from the partially depleted mast cells, that the effect of compound 48/80 was masked. It is concluded that those irritants which produce neurogenic oedema cause release of one or more substances from sensory nerve terminals, and that at least part of the oedema produced is mediated by amines released from mast cells ( Figure 5).…”

“…The object of the experiments on capsaicin-desensitized rats reported here was a more quantitative examination of the extent to which sensory nerve stimulation contributes to the oedema produced by a variety of irritants. Since Kiernan (1972a) has suggested that mast cells are involved in antidromic vasodilatation, another series of experiments was performed in which rats were pretreated with compound 48/80, to establish the role of mast cells as mediators of neurogenic oedema.…”

Neuronal plasticity of the “brain–skin connection”: stress-triggered up-regulation of neuropeptides in dorsal root ganglia and skin via nerve growth factor-dependent pathways

“…The stress-induced increased expression of substance P (SP) in skin nerve fibers and of cutaneous nerve growth factor (NGF) consequently lead to the development of neurogenic skin inflammation, recognized by its classical features of mast cell degranulation, vasodilatation, and plasma extravasation [12,13]. Both SP and NGF are now widely acknowledged as cardinal immunomodulators and prevailing stress markers in different settings [4,[14][15][16].…”