Free fatty acid patterns in normal and multiple sclerosis white matter

The relative compositions of free fatty acids (FFA) in white matter from six multiple sclerosis (MS) and seven control brains were determined by gas chromatography. The major components of all samples were oleic, stearic and palmitic acids, with lesser amounts of arachidonic acid, and a long chain fatty acid, identified as 24:4. MS samples had significantly less of the 24:4 fraction compared with controls, but no other differences were noted. The spectrum of FFA was similar in most respects to those reported for phosphatidylcholine and cholesterol esters. This supports current theories that a major pathway of lipid catabolism in the brain involves transfer of fatty acids from phosphatidylcholine to cholesterol.