脱髄の生化学

Biochemistry in demyclination.

はじめに

　脱髄疾患の病因が，近年，ウイルス学，免疫学そして生化学的面から研究され，多くの成果が報告されてきており，ミエリンの崩壊の機序が，分子レベルで説明されるようになってきている。今回，筆者らは，脱髄疾患の中心的疾患である多発性硬化症と遣伝性脱髄疾患であるadrenoleukodystrophy（ALD）とgloboid cell leukodystrophy（GLD）における脱髄の機序について生化学的面から概説する。

(1) Adrenoleukodystrophy (ALD)

　ALD is a fatal x-linked hereditary demyelinating disorder with the involvement of adrenal cortex. The characteristic biochemical abnormality of ALD is the increase of very long saturated fatty acids (VLCFA) in cholesterol esters, sphingolipids and glycerophospholipids and the disturbance of VLCFA metabolism was supposed to be the primary metabolic defect in this disorder. Singh et al. reported that the oxidation of VLCFA was impaired and peroxisomal very long chain fatty acyl-CoA synthetase was defective in ALD and Tsuji et al. found that the activities of microsomal fatty acid elongation were also increased in fibroblasts from patients with ALD.