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Effect of Docosahexaenoic Acid on the Synthesis of Phosphatidylserine in Rat Brain Microsomes and C6 Glioma Cells
Author(s) -
Garcia Martha C.,
Ward Glenn,
Ma YeeChung,
Salem Norman,
Kim HeeYong
Publication year - 1998
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.1998.70010024.x
Subject(s) - docosapentaenoic acid , docosahexaenoic acid , phosphatidylserine , polyunsaturated fatty acid , phosphatidylcholine , microsome , biology , phospholipid , biochemistry , arachidonic acid , fatty acid , endocrinology , in vitro , enzyme , membrane
Docosahexaenoic acid (22:6n‐3) is the major polyunsaturated fatty acid (PUFA) in the CNS and accumulates particularly in phosphatidylserine (PS). We have investigated the effect of the 22:6n‐3 compositional status on the synthesis of PS. The fatty acid composition of brain microsomes from offspring of rats artificially reared on an n‐3‐deficient diet showed a dramatic reduction of 22:6n‐3 content (1.7 ± 0.1%) when compared with control animals (15.0 ± 0.2%). The decrease was accompanied by an increase in docosapentaenoic acid (22:5n‐6) content, which replaced the 22:6n‐3 phospholipids with 22:5n‐6 molecular species, as demonstrated using HPLC/electrospray mass spectrometry. The n‐3 deficiency did not affect the total amount of polyunsaturated phospholipids in brain microsomes; however, it was associated with a decrease in the total polyunsaturated PS content and with increased levels of 1‐stearoyl‐2‐docosapentanoyl (18:0/22:5n‐6) species, particularly in phosphatidylcholine. Incorporation of [ 3 H]serine into PS in rat brain microsomes from n‐3‐deficient animals was slightly but significantly less than that of the control animals. Similarly, C6 glioma cells cultured for 24 h in 22:6n‐3‐supplemented media (10–40 µ M ) showed a significant increase in the synthesis of [ 3 H]PS when compared with unsupplemented cells. Our data show that neuronal and glial PS synthesis is sensitive to changes in the docosahexaenoate levels of phospholipids and suggest that 22:6n‐3 may be a modulator of PS synthesis.