Effects of Alkali-metal Ions on Phospholipid and Triglyceride Synthesis in Rat Liver Slices.

The influence of alkali-metal ions on the incorporation of labeled precursors into phospholipids and triglycerides was studied in rat liver slices. By use of acetate-l-G4 and ~a1mitate-l-C~~ as lipid precursors, a comparison was made of the pathway from acetate to phospholipid and the pathway from palmitate to phospholipid. While the rate of incorporation of palmitate-l-C1* into phospholipids and triglyceride fatty acids was virtually independent of the alkalimetal ion present in the medium, the rate of incorporation of acetate-1 -C14 into the same compounds was strongly influenced by the alkali-metal ions, the highest incorporations being obtained with potassium and rubidium. Under the same conditions lithium appears to have an inhibitory effect. The effects of the alkali-metal ions on phospholipid and triglyceride synthesis in liver are located on the pathway between acetate and long-chain fatty acids.