Induction of fatty acid synthesis in cultured mammalian cells: Effects of cycloheximide and x‐rays

It was found that L cells deprived of exogenous fatty acids responded adaptively by increased synthesis of fatty acids. This adaptive increase was found to be sensitive to cycloheximide presented at the time of removal of exogenous lipids, but was not sensitive to cycloheximide added six hours after removal of lipids. It was concluded that the adaptive increase in fatty acid synthesis represents a case of enzyme induction. The effect of x‐rays on this process was studied. It was found that induction was inhibited to a greater extent than total protein synthesis. Factors of potential importance to such an effect are discussed.