Enigmatic effect of cellular ATP on fatty acid biosynthesis: Stimulation by moderate decrease and inhibition by increase of cellular ATP

The cellular ATP concentration was tested for its effect on fatty acid biosynthesis from glucose in hepatocytes. ATP was manipulated by adding increasing concentrations of cycloheximide, amytal, atractyloside, 2,4-dinitrophenol or adenosine. A slight decrease in cellular ATP coincided with a stimulation of fatty acid biosynthesis whereas a further lowering of cellular ATP resulted in a gradual inhibition. Increasing the cellular ATP level by titration with adenosine had the opposite effect. These results are in line with the suggestion that fatty acid biosynthesis from glucose is an energy-yielding process which is stimulated by a moderate drop in cellular ATP.