Normal human skin demonstrates marked site-variation of tenascin expression, not correlated to epidermal proliferation (Ki-67 binding).

In disorders of the skin characterized by epidermal hyperproliferation, it has been demonstrated that the expression of tenascin in the dermis is markedly increased. In normal dermis, however, tenascin is slightly expressed in the upper dermis beneath the basal membrane. Using an immunohistochemical approach, tenascin expression (T2H5 binding) and recruitment of cycling epidermal cells (nuclear binding to Ki-67) were studied in normal skin at various localizations of the body surface. Whereas recruitment of cycling epidermal cells did not show a significant body-site variation, tenascin expression was most pronounced at the extensor surface of the lower arm. In normal skin, no significant correlation was observed between both phenomena in striking contrast to the well-established correlation in hyperproliferative skin conditions.