Ethanolamine Phospholipid Metabolism in Myelinating Rat Brain

Abstract

3H-1abelled ethanolamine phospholipids were isolated from the brains of 13-day-old rats after intracerebral injection of [9,1O-3H]palmitic acid. Groups of rats of the same age were injected intracerebrally with preparations derived from the whole labelled fraction, the ethanolamine plasmalogen-depleted fraction, or [14C]palmitic acid. A study of the distribution of radioactivity in phospholipids and sphingolipids, 2 hr after injection, indicates that the alkenyl chains of ethanolamine plasmalogen are effective precursors of the acyl groups of sphingomyelin and cere-broside. This role of plasmalogen is discussed in terms of the properties and distribu-tion of plasmalogenase, aldehyde dehydrogenase, and fatty acid chain-lengthening enzymes in brain.