The aim of this study was to investigate the effects of cutaneous sensory nerves on MC-driven inflammatory responses.
Passive cutaneous anaphylaxis, a model for type I allergic skin responses, was studied in the presence or absence of sensory nerves by using a murine model of selective cutaneous denervation.
Passive cutaneous anaphylaxis was significantly impaired in the absence of sensory nerves. This effect was not a result of an alteration of mast cell numbers in denervated skin. Moreover, IgE-mediated activation of mast cells was markedly decreased in denervated compared with normal skin. Notably, pretreatment of mice with selective antagonists of the neuropeptides substance P and/or calcitonin gene-related peptide also resulted in decreased inflammatory responses after MC activation.
These data suggest that sensory skin nerves augment MC-driven inflammatory responses by releasing neuropeptides that increase MC degranulation.