THE FORMATION OF GLYCEROPHOSPHATIDES FROM C14-LABELLED PRECURSORS IN RAT BRAIN SLICES

The relative incorporation of a number of C14-labelled precursors into the phosphatides of surviving rat brain and liver slices was examined. In addition, the distribution of radioactivity within the individual phosphoglycerides was determined for each precursor. Acetate was the only precursor that contributed considerable radioactivity to the fatty acid portion of the phosphatide molecule. The other precursors donated their radioactivity to the non-fatty acid portion of the glycerophosphatide molecule, both in brain and liver tissue. In brain it was found that ethanolamine was the most effective precursor, followed by serine, choline, glycerol, acetate, and glycine. In liver the order was acetate, glycerol, serine, choline, and glycine. Aerobic conditions and an adequate carbohydrate metabolism were essential for optimum incorporation of the precursors into the phosphatides of brain slices.