Human Sebaceous Gland Lipids: In Vitro Incubations with 14C-Labelled Compounds

Human sebaceous glands were dissected (at 25–40x magnification) under sterile conditions from scalp specimens obtained during neurosurgical procedures. Isolated glands were incubated with 14C-glucose or 14C-branched amino acids in sterile chambered Petri dishes. Lipids were extracted, separated by thin-layer chromatography (TLC), scraped from the thin-layer plate, re-extracted and weighed, and the incorporated radioactivity of each fraction was measured by liquid scintillation counting. Squalene, wax esters, triglycerides and cholesterol were identified by TLC, and their presence was confirmed by the Liebermann-Burchardt reaction. Cholesterol estes were not identified by either technique. Radioactivity was found in most lipid fractions, at least in small amounts. Specific activity was highest in the triglyceride fraction. Although free fatty acids were not visualized by TLC, radioactivity was present in the area to which free fatty acids would be expected to migrate