Abstract: | Abstract— Elongation of mitochondrial fatty acids was studied in whole brain samples from rats before, during and after the period of myelination. The mitochondria were isolated by centrifugation in a discontinuous sucrose gradient and incubated under N2 in a medium containing NADH, NADPH, ATP and acetyl-1-14C]coenzyme A. Fatty acids were extracted, methylated and analysed by gas-liquid chromatography. A distinct pattern emerged in which brain mitochondria from rats undergoing myelination synthesized longer chain fatty acids preferentially, particularly C22:4. Mitochondria from brains of mature rats synthesized shorter chain fatty acids preferentially, mainly C18:0 and C20:4. We suggest that eicosamonoenoic acid (C22:1) is a precursor in vivo of nervonic acid (C24:1). |