THE WATER CONTENT OF THE STRATUM CORNEUM .3. EFFECT OF PREVIOUS CONTACT WITH AQUEOUS SOLUTIONS OF SOAPS AND DETERGENTS

[摘要] After soaking in water or in aqueous solutions of soaps or synthetic detergents, thin sheets of callus are less flexible than before soaking. Soaking in water does not reduce the water-holding capacity of cornified epithelium very much. Soaking in soap solutions reduces the water-holding capacity as much as does soaking in synthetic detergent solutions. Reduction of the water-holding capacity is not measurably altered by the addition of sodium triphosphate to either the soap or the synthetic detergent solutions. There are water-soluble nitrogenous materials which can be extracted from calluses or from intact cornified epithelium by water alone or by aqueous solutions of soap or synthetic detergents. A soap solution extracts as much of these materials as do synthetic detergent solutions. In all of these extractives there appears to be a relatively constant amount of aromatic amino acids. There exists a clinical impression that the routine use of commercial household synthetic detergents is more damaging to the skin than is the routine use of household soaps. Data reported here do not indicate that the chemicals commonly used in the manufacture of household detergents alter cornified epithelium any differently than does a coconut oil soap. If synthetic detergents are more damaging to the skin than soap, the mechanism of this action has not been determined by the investigations or cornified epithelium reported in this paper.