A possible function of structural lipids in the water-holding properties of the stratum corneum.

In order to clarify the possible role of lipids in the water-holding property of stratum corneum, the forearm skin of 6 healthy male volunteers was treated with acetone/ether (1/1) for 1, 5, 10, and 20 min. A prolonged treatment period of 5-20 min produced a chapped and scaly appearance of the stratum corneum without any inflammatory reactions. Under these conditions, there was a marked decrease in the water-holding capacity of the stratum corneum accompanied by a considerable and selective loss of intercellular lipids such as cholesterol, cholesterol esters, and phospholipids. These impairments persisted until day 4 after treatment. Electron microscopic observation of the altered stratum corneum revealed that naturally occurring intercellular materials were absent, leaving the area with the appearance of a vacant space. These findings suggest an additional and essential role of the specific structural lipids for the water-holding properties of the stratum corneum.