Intermediates of unsaturated fatty acid oxidation are incorporated in triglycerides but not in phospholipids in tissues from patients with mitochondrial beta-oxidation defects
W. Onkenhout et al., Intermediates of unsaturated fatty acid oxidation are incorporated in triglycerides but not in phospholipids in tissues from patients with mitochondrial beta-oxidation defects, J INH MET D, 24(3), 2001, pp. 337-344
The fatty acid composition was determined of liver, skeletal muscle and hea
rt obtained post mortem from patients with medium-chain acyl-CoA dehydrogen
ase deficiency (MCADD), multiple acyl-CoA dehydrogenase deficiency (MADD) a
nd very long-chain acyl-CoA dehydrogenase deficiency (VLCADD). Increased am
ounts of 4-decenoic acid 10:1(n-6), 5-dodecenoic acid 12:1(n-7), 5-tetradec
enoic acid 14:1(n-9), 5,8-tetradecadienoic acid 14:2(n-6) and 7,10-hexadeca
dienoic acid 16:2(n-6)-intermediates of unsaturated fatty acid oxidation-we
re found. Fractionation into different lipid classes showed that these fatt
y acids were exclusively present in the triglyceride fraction. They could n
ot be detected in the free fatty acid fraction or in the phospholipid fract
ion. Our results suggest that intermediates of unsaturated fatty acid oxida
tion that accumulate as a consequence of MCADD, MADD and VLCADD are transpo
rted to the endoplasmic reticulum for esterification into neutral glyceroli
pids. The pattern of accumulation is characteristic for each disease, which
makes fatty acid analysis of total lipid of post-mortem tissues a useful t
ool in the detection of mitochondrial fatty acid oxidation defects in patie
nts who died unexpected, for example with sudden infant death syndrome.