Mitotic Activity in the Skin of Mice Deficient in Essential Fatty Acids

Abstract

THE most striking difference between the skin of essential fatty acids deficient mice and that of normal mice is the number of layers of cells in the epidermis; the epidermis of essential fatty acids deficient mice is nearly three times thicker than normal¹. A similar difference has been found in the skin of rats kept on a fat-free diet². The greater thickness of the epidermis under these dietary conditions could conceivably have resulted from either: (a) a decrease in the rate of epidermal keratinization and cell sloughing; (b) an increase in the rate of cellular proliferation; or (c) a combination of these. The accumulation of abnormally large amounts of lipid in the cells of the distal epidermal layers of essential fatty acids deficient mice¹ suggested that these cells may, indeed, keratinize and slough at a slower rate than normal. The mitotic indices of the epidermis of normal and essential fatty acids deficient mice are compared in the present communication in an effort to deal with the second and third of the possible explanations for epidermal thickening.