Maternal dietary fish oil enriches docosahexaenoate levels in brain subcellular fractions of offspring

Abstract

Prompted by the speculated essentiality of docosahexaenoic acid (DHA) for neural development, this study was undertaken to investigate the incorporation of (n-3) fatty acids in the maternal diet into various phospholipids of infant rat brain subcellular fractions: microsomes (Ms), synaptosomes (Sy), myelin (My), and mitochondria (Mt). Two groups of infant rats were nourished by dams fed diets containing 20% of either corn oil (CO) or menhaden oil (MO) from 2 until 12 days of age. DHA but not eicosapentaenoic acid (EPA) was distributed to all subcellular fractions of infant rats in the CO group. The levels of DHA were higher in Ms and Mt than Sy and My, and higher in phosphatidylethanolamine (PE) and phosphatidylserine (PS) than phosphatidylcholine (PC) and phosphatidylinositol (PI). The MO feeding enriched DHA in PE of all subcellular fractions, PS of all subcellular fractions, except My, PC of Sy, My and Mt, and PI of My. EPA was enriched in phospholipids in all subcellular fractions, except mitochondrial PS of the MO group. In the MO group, the ratios of EPA/DHA, ranging from 0.01 to 0.85, in all subcellular phospholipids were markedly lower than that found in the mother's milk (i.e., 1.5), suggesting an ability to elongate and desaturate EPA to DHA and/or disproportional uptake of the fatty acids by the brain. In PE of all subcellular fractions, the increased levels of DHA and EPA, with a concomitant reduction of arachidonic and/or linoleic acid, yielded higher ratios of total (n-3)/(n-6) fatty acids in the MO than the CO group. The inclusion of preformed DHA and EPA in the maternal diet provides an effective means to enrich these fatty acids in developing brains.

Molecular cloning of rat mitochondrial 3-hydroxy-3-methylglutaryl-CoA lyase and detection of the corresponding mRNA and of those encoding the remaining enzymes comprising the ketogenic 3-hydroxy-3-methylglutaryl-CoA cycle in central nervous system of suckling rat

“…Significantly, potentially ketogenic polyunsaturated fatty acids (PUFAs) such as linoleic, arachidonic and docosahexaenoic acids [15] exhibit facile transfer across the blood-brain barrier during the suckling period [16,17]. Furthermore recent hybridization studies in situ [18,19] have demonstrated the localization of the peroxisome proliferator-activated receptor α (PPARα), a nuclear transcription factor that is activated by a variety of PUFA ligands [20,21], to certain brain regions.…”

Pre- and Postweaning Iron Deficiency Alters Myelination in Sprague-Dawley Rats

“…Phospholipid fatty acid analyses were conducted according to the methods of Yeh et al [1993]. Briefly, myelin fractions from hindbrain homogenates were resuspended in 1.2 ml of deionized water and added to 20 ml of chloroform:methanol (2:1, v/v) for lipid extraction with butylated hydroxytoluene as the antioxidant.…”

Modification of milk formula to enhance accretion of long‐chain n−6 and n−3 polyunsaturated fatty acids in artificially reared infant rats

“…The gas chromatographic conditions were the same as those described elsewhere (38). For fatty acid analysis of phospholipid species, the lipid extracts were separated into phosphatidylcholine (PC) and phosphatidylethanolamine (PE) by thin-layer chromatography using silica G plates and a solvent mixture of chloro-form/methanol/petroleum ether (bp 35-60°C)/acetic acid /boric acid (40:20:30:10:1.8; vol/vol/vol/vol/wt) as described in a previous study (39). The isolated individual phospholipids were transmethylated and analyzed by gas chromatography (38).…”