RÉSUMÉ
BACKGROUND: The changes in lipid composition during epidermal differentiation has been reported in human and animal models. Because of the difficulties in getting adeguate specimens from human subjects, the authors used easily obtainable circumcised prepuce for lipid analysis. OBJECTIVE: To investigate the changes in lipid composition duriig cornification of the epidermis, the lipid compositions of whole epidermis and stratum corneum were analyzed by thin layer chromatography(TLC). METHODS: From circumcied prepuce whole epidermis and stratum orneum were separated by 10mM EDTA(ethylene diamine tatraacetate) in PBS(phosphate-buffered saline) or heat(60C), and 0.5% trypsin in PBS respectively. Lipids were extracted with methanolctloroform-HO mixture(4:2:1.6, v/ v, Bligh-Dyer solvent), TLC was performed and lipid composition was quantitated by photodensitometer. RESULTS: In the composition of stratum corneum lipids, sphingoliids were the highest(33.3+2.9%) followed by cholesterol, free fatty acids and cholesterol esters in cleceasing order, there were small percentages of triglycerides, cholesterol sulfate and squalene. CONCLUSION: In this study the lipid composition of epidermis was similar to that of stratum corneum rather than those of previous reports on epidermal lipids, which may indicate the regional characteristics of epidermal/stratum orneum lipids in hyperkeratotic prepuie.