Localization of substance P-immunoreactive nerve fibers in the human digital skin.

Substance P-immunoreactive nerve endings were localized in human digital skin by the use of indirect immunohistochemical technique. It was found that substance P-like immunoreactivity was present in free nerve endings in the dermal papillae and in the epidermis. Some Meissner's corpuscles also contained substance P positive nerve endings. Furthermore, substance P-immunoreactive nerves were localized in close connection to sweat gland ducts and blood vessels. The functional significance of these findings was discussed with regard to pain mediation and inflammatory response.