On the Phospholipid Metabolism of Glial Cell Primary Cultures: Cell Characterization and Their Utilization of 1-Alkyl-Glycerophosphoethanolamine

Abstract: Primary cultures prepared from newborn rat brain were grown for 16 or 17 days in culture. Addition of brain extract from newborn rats to the medium stimulated the maturation of astrocytes and the development of oligodendrocytes. Both cell types were characterized by morphology and by immunohistochemistry. The phospholipid composition of these cells was estimated. Incubations were performed with l-³H]alkyl- sn -glycerophosphoethanolamine in varying concentrations for 3 h. About one-third of the substrate supplied was internalized by the cells. Several enzymic reactions were observed. The acylating enzyme system was the most active one—a K _m was determined with 5 nmol intracellular 1-alkyl- sn -glycerophosphoethanolamine/mg cell protein. Plasmalogen formation was rather low. 1-Alkyl- sn -glycerol, a hydrolysis product, was found in small amounts. Some radioactivity was also incorporated into the phosphatidylcholine fraction.