Abstract

The conversion of [1-14C]16:0 to very-long-chain saturated fatty acids (VLCSFA) was greater in fibroblasts from adrenoleukodystrophy (ALD) patients than fibroblasts from normal subjects. Added 23:1(n-9) decreased the formation of VLCSFA from [1-14C]16:0 in ALD fibroblasts to the value found in normal fibroblasts. Chain-elongation as well as extensive chain-shortening of added 20:1(n-9), 22:1(n-9), 23:1(n-9) and 24:1(n-9) occurred in both normal and ALD fibroblasts, with chain-shortening being less in ALD than in normal fibroblasts. Added 18:1(n-9) together with 22:1(n-9) reduced the levels of both VLCSFA and total n-6 and n-3 polyunsaturated fatty acids (PUFA) in normal and ALD fibroblasts. The levels of total (n-6) and (n-3) PUFA but not the levels of VLCSFA were readily restored by culturing the cells in the presence of 18:1(n-9), 22:1(n-9), 18:2(n-6) and 18:3(n-3). The results are consistent with added monounsaturated fatty acids reducing levels of VLCSFA in ALD fibroblasts by depressing their biosynthesis from 16:0. They also support the use of oils rich in long chain monoenes as a dietary therapy for ALD patients but caution that the PUFA status of ALD patients should be monitored with a view to dietary supplementation, if necessary, with PUFA.