GLUTAMATE-LIKE AND ASPARTATE-LIKE IMMUNOREACTIVITIES IN HUMAN NORMAL AND INFLAMED SKIN

The presence of glutamate/aspartate-like immunoreactivity was studied in normal human skin and in skin with gold-induced inflammation. In no rmal skin all epithelial cells were glutamate and, apparently more wea kly, aspartate immunoreactive. Both glutamate and aspartate immunoreac tivities were also found in macrophage-like, HLA-DR positive cells in the dermis and in the epidermis. The intensity of glutamate and especi ally aspartate-like immunoreactivities seemed to be increased in the e pidermis and dermis of the inflamed as compared to the normal skin, an d this increase was particularly pronounced in the HLA-DR positive (de ndritic) cells in the epidermis. Numerous cells, often of the mononucl ear type, in the superficial dermis expressed glutamate- and aspartate -like immunoreactivities in the inflamed skin and many of these were H LA-DR positive. The functional role of glutamate and aspartate in norm al skin, and the significance of the increase in the levels of these a mino acids in several cell populations in the inflammatory skin is not known, but modulatory or protective roles may be considered. High con centrations of these amino acids could also induce cell damage. Moreov er, the macrophage-like cells in the human skin may have a role in the processing of glutamate and aspartate on a recycling basis.