Esterification of cholesterol in the skin.

Unna and Golodetz (1, 2) found that the concentration of sterol esters in stratum cor-neum was greater than in epidermis and postulated that esterification of cholesterol accompanies keratinization. In confirmation of their findings, Kooyman (3) reported that the proportion of sterols in ester linkage in mal-pighian layer of the palmar skin was 7.4% versus 18.1% in the stratum corneum. Although these differences have not been verified, a higher proportion of esterified sterols in surface lipids (ranging from 43 to 65%) as opposed to epidermal lipids (8-18%) has been amply documented (4, 5, 6).