Steryl esters and their relationship to normal and diseased human central nervous system.

The composition and distribution of steryl esters in human diseased or developing brain tissue has been studied. The abnormal brain conditions included sudanophilic leukodystrophy, multiple sclerosis plaque, subacute sclerosing panencephalitis, and an old cerebral infarction and two types of brain-derived tumors. In addition to the above abnormal tissue, steryl esters were also examined in developing and normal adult human brain. It was found upon subcellular fractionation that the steryl ester was localized mainly in the soluble nonparticulate material. A cholesteryl ester-rich fraction, floating on top of distilled water after centrifugation, was recovered only in the developing brain or in instances where there was myelin damage. The sterol portion of the steryl ester was largely cholesterol. The fatty acid moiety was mainly composed of C(16), C(18), and C(20) fatty acids. The dominant fatty acid was oleic acid, and the proportion of this fatty acid increased in demyelination. Although there were great differences in the quantities of steryl ester found, the fatty acid profiles of normal developing and adult brain were quite similar. As has been noted by others, the fatty acid composition of brain steryl esters most closely resembles that of brain phosphatidylcholine.