title: Lipid compositions of cells isolated from pig, human, and rat epidermis.
abstract: Epidermal slices from pig, human, and rat skin were treated with dilute buffered trypsin solution (0.005%, w/v), and suspensions of mixed basal and spinous cells were obtained in good yield. Total lipids accounted for approximately 8% of the pig, 10% of the human, and 20% of the rat epidermal cell (dry weight). Phospholipids in pig, human, and rat cells accounted for, respectively, 62%, 53%, and 35% of the total lipids. Phosphatidylcholine (34-38%), phosphatidylethanolamine (18-23%), and sphingomyelin (17-21%) were major compounds in all species. The major neutral lipids were sterols (mostly cholesterol) and triglycerides. Free fatty acids were a major lipid class in pig and human cells, whereas wax esters were a major component in rat epidermal cells. Nearly half (45%) of the sterols in rat cells but less than 10% of those in pig and human cells were esterified. Cholest-7-ene-3beta-ol accounted for 20% of the total sterols in rat cells. Cholesteryl sulfate and ceramide were minor lipids in the three species. The predominant glycosphingolipid (greater than 99%) was glucosylceramide, which accounted for 7% and 9%, respectively, of the total lipids in pig and human cells. A significant proportion (pig, 17%; human, 11%) of the fatty acids in the glucosylceramides were C26:0 and C28:0.
mesh_terms: D000818:Animals; D002518:Ceramides / Q000032:analysis; D002788:Cholesterol Esters / Q000032:analysis; D005227:Fatty Acids / Q000032:analysis; D006028:Glycosphingolipids / Q000032:analysis; D006801:Humans; D008055:Lipids / Q000032:analysis* / Q000302:isolation & purification; D010743:Phospholipids / Q000032:analysis; D051381:Rats; D012867:Skin / Q000032:analysis*; D013045:Species Specificity; D013552:Swine
chemical_list: D002518:Ceramides; D002788:Cholesterol Esters; D005227:Fatty Acids; D006028:Glycosphingolipids; D008055:Lipids; D010743:Phospholipids