| Abstract: | Abstract— —Cholesteryl esters were isolated from the cerebral cortex and white matter of human brains at different ages, and their concentration and composition determined. The esters were separated from other lipids by chromatography on silicic acid and finally purified by TLC. The fatty acids were converted to the methyl esters by alkaline trans-methylation and analysed by GLC. A TLC method was elaborated for quantitative determination of small amounts of cholesteryl esters in the presence of free cholesterol. The concentration of cholesteryl esters was only 0·1–0·2 per cent of the total cholesterol content of cerebral tissue in older children and adults. During early myelination the concentration was many times greater, especially in the white matter but it never exceeded 2 per cent of the total cholesterol in any subject. The major fatty acids of human brain cholesteryl esters were oleic, palmitic, palmitoleic and arachidonic acid. After completion of myelination, arachidonic acid constituted the major fatty acid. There were fairly small differences in the fatty acid pattern of the cholesteryl esters between grey and white matter, but the concentration of polyunsaturated fatty acids was larger in the grey matter. Cholesteryl esters appear to play an important role in the metabolism of the phosphoglyceride fatty acids in cerebral tissue. |
