Prostaglandins, Leukotrienes and Essential Fatty Acids

On a per-weight basis, the brain is the organ richest in lipids, including a remarkable proportion of polyunsaturated fatty acids (PUFAs) of the omega 3 series, namely eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. The cerebral effects of exogenous DHA likely depend on its degree of incorporation into neuronal phospholipids andon itsdistributionamong thevariousbrain structures, after intake.Hence, because PUFAs are not evenly distributed among the brain phospholipid classes and because the existence of classspecific phospholipases that regulate their turnover, we sought to investigate the incorporation of omega 3 PUFAs in selected brain areas regions and specific phospholipid classes. Rats (n1⁄47) were administered, by oral gavage, 100 mg/kg/d of a commercially available fish oil (containing 84% of long-chain omega 3 fatty acids, of which 38% of DHA and 46% of EPA). Control rats (n1⁄47) received liquid paraffin. This treatment was continued for 30 days. Thereafter, we dissected three areas, namely the hippocampus, the striatum, and the cortex. Quantization of individual phospholipid classes and theirmolecular specieswas performed by ESI-MS/MS. Principal component analysiswas used to examine the variation of themolecular lipid profiles (as percentage) induced by omega 3 supplementation. Our results show that provision of omega 3 fatty acids to rats results in their incorporation into brain phospholipids, the extent of which is lower in the striatum as compared with cortex and hippocampus. These data might in part explain the mixed therapeutic results obtained in neurological disorders, many of which are likely region-specific. & 2010 Elsevier Ltd. All rights reserved.