A change in the cerebrosides and sulfatides in a demyelinating nervous system. Development of the methodology and study of multiple sclerosis and Wallerian degeneration.

This report described a new method for the microanalysis of sphingolipids and its application for the characterization of cerebrosides and sulfatides in multiple sclerosis brain and rat sciatic nerves undergoing Wallerian degeneration. Tissue was extracted with isopropanol/hexane (20:78), and the total lipids obtained were subjected to benzoylation-desulfation. A portion of this was directly analyzed by silica-column high performance liquid chromatography for the determination of nonhydroxycerebroside, hydroxycerebroside, nonhydroxysulfatide, and hydroxysulfatide. Another portion was fractionated by thin-layer chromatography, and the spots corresponding to the sphingolipid derivatives were eluted. The material from each spot was analyzed by reverse phase high performance liquid chromatography for its homolog composition. With this new procedure the concentrations and homolog compositions of cerebrosides and sulfatides were measured in plaque, periplaque, and normal-appearing white matter from brains of multiple sclerosis patients and Wallerian degenerated rat sciatic nerves distal to the nerve transection. One piece of plaque studied contained only 1.86, 2.76, 0.60, and 0.45 nmol of nonhydroxycerebroside, hydroxycerebroside, nonhydroxysulfatide and hydroxysulfatide/mg of protein, respectively. These concentrations are less than 1% of those found in normal white matter. Periplaques were found to contain concentrations of these sphingolipids between those of plaque and normal white matter. The levels of these sphingolipids in degenerative nerves were 10-20% below normal the third day after the nerve was severed and about 70% below normal after 10 days. The rate of decrease lessened from ten days to 55 days. The homolog compositions of these sphingolipids in both multiple sclerosis brain and degenerating nerves were similar to those in the control. The implications of these findings and the advantages of this new analytical method are discussed.