THE ROLE OF LIPIDS IN THE EPIDERMAL BARRIER TO WATER DIFFUSION.

The diffusion of tritiated water through hairless mouse skin and human abdominal autopsy skin was determined in vitro prior and subsequent to the application of organic solvents to the epidermal side of the skin. The classes of extracted lipids were separated by thin-layer chromatography. The amounts and types of lipids extracted were correlated with changes in tritiated water diffusion. Seven classes of lipids were identified from hairless mouse skin extracted with acetone, diethyl ether and chloroform, but only minimal amounts of four classes of lipids were identified from skin extracted with dimethylsulfoxide. All of the solvents increased the rate of diffusion of tritiated water, but there was no correlation between the type or amount of lipid extracted and the degree of alteration of the water barrier function. Results obtained with human abdominal autopsy skin were similar in that dimethylsulfoxide removed a minimal amount of lipid, but markedly increased the diffusion rate of tritiated water. [ABSTRACT FROM AUTHOR]