Effects of alkaline on horny layer cellularity.

The microscopical changes of plantar Str. corneum after immersion in alkaline were investigated. For this purpose a test system was used in which unexcised skin of guinea pig hind feet was exposed and subsequently analysed by the FITC-staining method. The effect of KOH on the Str. corneum consisted in an immediate swelling of the outer cell layers which was followed by a further increase in cell volume. Cells became separated layer by layer after maximal swelling. There is a high and constant rate of cell loss, when treated superficial cells are repeatedly removed as compared to permanent immersion. Thus, the buffering capacity of the treated outer cell layers has a rate limiting effect upon alkaline-induced cell loss in the Str. corneum.