Cutaneous innervation in man visualized with protein gene product 9.5 (PGP 9.5) antibodies

Summary Using antibodies to the neuronal cytoplasmic protein, protein gene product 9.5 (PGP 9.5) the cutaneous innervation in man was investigated. The distribution of PGP 9.5 immunoreactive nerve fibers was compared with the distribution of nerve fibers immunoreactive to neuron specific enolase, neurofilament proteins, calcitonin gene related peptide, vasoactive intestinal polypeptide and neuropeptide Y. PGP 9.5 immunoreactive nerve fibers were found in the epidermis, dermis, in Meissner's corpuscles, innervating Merkel cells, around blood vessels, sweat glands and hair follicles. Merkel cells were also PGP 9.5 positive. The labelled nerve fibers included sensory and autonomic fibers, visualizing the whole innervation of the human skin. The number of positive fibers and the intensity of the fluorescence was greater with PGP 9.5 antibodies than with any of the other markers included. Thus, PGP 9.5 antibodies may serve as a tool for investigations of cutaneous innervation, reinnervation and nerve regeneration in different clinical conditions.