Some Factors Affecting C14-Acetate Incorporation into Polyunsaturated Fatty Acids of Skin

Newborn mouse skin and human preputial skin were incubated for varying time periods in different media containing 1-C14-acetate. Fatty acids were isolated by conventional chromatographic procedures and their radioactivity monitored. Complete tissue culture medium and serum or an oxygen atmosphere enhanced acetate uptake compared to that in phosphate buffer. This increase affected saturated acids more than unsaturated. Insulin increased incorporation, especially into PUFA, but prostaglandin E2 exerted the opposite effect in some experiments. Incorporation into all acids increased with time, although there was a tendency to fall off or even plateau except in the case of polyunsaturated (PUFA) fractions. Individual PUFA, including linoleic and linolenic acids, showed a linear increase at widely different rates. The labeling rate of arachidonic acid tended to increase after about five hours