Changes in the composition of two molecular species of ethanolamine plasmalogen in normal human myelin during development.

Changes in the ratio of two molecular species of ethanolamine plasmalogen, PI-LE-1 and PI-PE-2, of human central nervous system myelin during development were measured by a TLC procedure. The ratio was found to decrease sharply with age up to 6 months as a result of an increase in the amount of PI-PE-2, believed to be a unique myelin lipid with 18:1 chains in both positions of the glycerol. The ratio continued to decrease gradually with age and did not reach the adult level until an age of 17 years.