A detailed account of NPY-immunoreactive nerves and cells of the human skin. Comparison with VIP-, substance P- and PHI-containing structures.

Neuropeptide Y (NPY)-like immunoreactivity has been found in autonomic nerve terminals and fibres of the normal human dermis by the use of indirect immunohistochemistry. Also a granular immunoreactivity was observed in the basal cells of the epidermis as well as in the cells of the outer root sheath of hair follicles. Thus, NPY should be considered when examining the role of different autonomic neurotransmitter candidates. Furthermore, NPY and norepinephrine may, at this level, serve together as co-transmitters or co-modulators of autonomic function. Finally, the immunoreactivity found in cells of the epidermis and the outer root sheath of hair follicles points to other functional effects so far not understood.