THE INCORPORATION OF α-GLYCEROPHOSPHATE-³²P INTO THE LIPIDS OF RAT BRAIN PREPARATIONS: I. GENERAL PROPERTIES

Studies have been carried out on the incorporation of 32 P-labeled α-glycerophosphate (α-G 32 P) into the lipids of preparations obtained from rat brain cerebral hemispheres. The optimal incorporating system contains Tris and phosphate buffers (pH 7.4), MgCl 2 , CoA, EDTA, NaF and ATP. The incorporation of α-G 32 P into monophosphoinositide was stimulated by CDP-choline, CDP-ethanolamine, CDP-glycerol and CTP. These nucleotides depressed the incorporation of α-G 32 P into phosphatidic acid. Microsomal preparations supported a high incorporation of α-G 32 P into phosphatidic acid, but the incorporation into monophosphoinositide was low compared with the whole homogenate. Similar observations were made with mitochondrial preparations undergoing oxidative phosphorylation with CoA added to the medium.