Studies in phospholipid metabolism. 2. Incorporation of metabolic precursors of phospholipids in choline deficiency

The incorporation of metabolic precursors of lipids was followed in the livers of rats fed a semisynthetic diet supplemented with, or deficient in, choline. In the early stages of choline deficiency no change was observed in the net incorporation of palmitic acid into liver lipids. Experiments with labelled ethanolamine, choline, and methionine showed that during choline deficiency the direct incorporation of choline into liver lecithins is unchanged, whereas the incorporation of the methyl group of methionine into lecithin, and ethanolamine into cephalins is decreased.