A COMPARATIVE-STUDY OF THE CYTOTOXICITY OF SKIN IRRITANTS ON CULTUREDHUMAN ORAL AND SKIN KERATINOCYTES

The cytotoxicity of irritants on human oral and skin keratinocyte cult ure models was compared. Keratinocytes were exposed to sodium lauryl s ulphate and benzalkonium chloride at concentrations of 10(-4)-10(-7) M for 24 h. Cytotoxicity was evaluated by changes in mitochondrial meta bolic activity (MTT assay) and plasma membrane integrity (LDH leakage) . Our results showed that oral and skin keratinocytes are equally sens itive to the irritants tested. There were marked similarities in susce ptibility between each cell type cultured from six individuals. The im munohistochemical staining pattern of both cell types resembled that o f the basal cell. These observations suggest that the skin keratinocyt e culture model may be useful in evaluating the cytotoxicity of agents which are irritants on either the skin or oral mucosa.