Effect of hexadecane on protein kinase C of pig epidermis.

The application of hexadecane on animals skin induces hyperkeratinization and hyperplasia of the epidermis, however, the initial mechanisms of the epidermal cell proliferation and keratinization by hexadecane stimulation remains unknown. Protein kinase C is reported to be one of the critical enzymes involved in proliferation and differentiation of various cells and tissues. Therefore we investigated the effects of hexadecane on protein kinase C in pig epidermis. Protein kinase C activity of the pig skin increased 10 min after topical application of hexadecane to the back of the pig, normalized at 30 min, and subsequently kept falling for 24 h. In studying hexadecane dropped on floating sliced pig skin in Krebs buffer, similar results were obtained for the short term. Immediately after the hexadecane treatment, protein kinase C activity was not altered as compared with that of the untreated skin. Thus, the alteration of the protein kinase C activity after the hexadecane treatment is not due to the direct effect of hexadecane on the enzyme, but is due to other as yet unknown mechanisms of epidermal cell kinetics in response to hexadecane stimulation. We discuss the mechanisms of protein kinase C activity alteration upon treatment with hexadecane.