Synthesis of lipids from acetate by human preputial and abdominal skin in vitro

Abstract

Lipogenesis in vitro from acetate-1-14C was studied in human preputial skin and abdominal skin. Radioactive lipids were separated by column chromatography on Florisil and by thin-layer chromatography on silica gel. Radioactivity was incorporated chiefly into the triglyceride, sterol, and polar lipid fractions, while lesser amounts of 14C were found in the hydrocarbon, wax, diglyceride, monoglyceride, and fatty acid fractions; labeling of steryl esters was minimal. On thin-layer chromatography, the radioactive polar lipids had mobilities similar to lysolecithin, phosphatidyl choline, phosphatidyl ethanolamine, and phosphatidic acid.The radioactive fatty acids of the different lipid fractions were separated by gas-liquid chromatography. The major 14C-labeled acids were 16:0 and 18:0. Radioactivity was also detected in acids 14:0, 15:0, 16:1, 18:1, 18:2, 20:0, 20:1, 22:0, 24:0, 24:1, and 26:0. No radioactivity could be detected in arachidonic acid, although this fatty acid comprises 9% of the chromatographed fatty acids. The pattern of incorporated 14C was different from the percentage mass composition of the fatty acids.Skin is therefore active in the biosynthesis of a wider variety of lipids than previously demonstrated.

Keywords

• lipogenesis
• triglyceride
• free sterols
• phosphoglycerides
• squalene
• diglycerides