The low levels of eicosapentaenoic acid in rat brain phospholipids are maintained via multiple redundant mechanisms
Brain eicosapentaenoic acid (EPA) levels are 250- to 300-fold lower than docosahexaenoic acid (DHA), at least partly, because EPA is rapidly β-oxidized and lost from brain phospholipids. Therefore, we examined if β-oxidation was necessary for maintaining low EPA levels by inhibiting β-oxidation with...
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| Format: | Article |
| Language: | English |
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Elsevier
2013-09-01
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| Series: | Journal of Lipid Research |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0022227520351312 |
| _version_ | 1819077162078044160 |
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| author | Chuck T. Chen Anthony F. Domenichiello Marc-Olivier Trépanier Zhen Liu Mojgan Masoodi Richard P. Bazinet |
| author_facet | Chuck T. Chen Anthony F. Domenichiello Marc-Olivier Trépanier Zhen Liu Mojgan Masoodi Richard P. Bazinet |
| author_sort | Chuck T. Chen |
| collection | DOAJ |
| description | Brain eicosapentaenoic acid (EPA) levels are 250- to 300-fold lower than docosahexaenoic acid (DHA), at least partly, because EPA is rapidly β-oxidized and lost from brain phospholipids. Therefore, we examined if β-oxidation was necessary for maintaining low EPA levels by inhibiting β-oxidation with methyl palmoxirate (MEP). Furthermore, because other metabolic differences between DHA and EPA may also contribute to their vastly different levels, this study aimed to quantify the incorporation and turnover of DHA and EPA into brain phospholipids. Fifteen-week-old rats were subjected to vehicle or MEP prior to a 5 min intravenous infusion of 14C-palmitate, 14C-DHA, or 14C-EPA. MEP reduced the radioactivity of brain aqueous fractions for 14C-palmitate-, 14C-EPA-, and 14C-DHA-infused rats by 74, 54, and 23%, respectively; while it increased the net rate of incorporation of plasma unesterified palmitate into choline glycerophospholipids and phosphatidylinositol and EPA into ethanolamine glycerophospholipids and phosphatidylserine. MEP also increased the synthesis of n-3 docosapentaenoic acid (n-3 DPA) from EPA. Moreover, the recycling of EPA into brain phospholipids was 154-fold lower than DHA. Therefore, the low levels of EPA in the brain are maintained by multiple redundant pathways including β-oxidation, decreased incorporation from plasma unesterified FA pool, elongation/desaturation to n-3 DPA, and lower recycling within brain phospholipids. |
| first_indexed | 2024-12-21T18:52:49Z |
| format | Article |
| id | doaj.art-478684076c734aa9a0a6ef70e6bb0cbb |
| institution | Directory Open Access Journal |
| issn | 0022-2275 |
| language | English |
| last_indexed | 2024-12-21T18:52:49Z |
| publishDate | 2013-09-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Lipid Research |
| spelling | doaj.art-478684076c734aa9a0a6ef70e6bb0cbb2022-12-21T18:53:41ZengElsevierJournal of Lipid Research0022-22752013-09-0154924102422The low levels of eicosapentaenoic acid in rat brain phospholipids are maintained via multiple redundant mechanismsChuck T. Chen0Anthony F. Domenichiello1Marc-Olivier Trépanier2Zhen Liu3Mojgan Masoodi4Richard P. Bazinet5Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada M5S 3E2; andDepartment of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada M5S 3E2; andDepartment of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada M5S 3E2; andDepartment of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada M5S 3E2; andNestlé Institute of Health Sciences SA, Campus EPFL, Quartier de l'innovation, bâtiment G, 1015 Lausanne, SwitzerlandTo whom correspondence should be addressed; Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada M5S 3E2; andBrain eicosapentaenoic acid (EPA) levels are 250- to 300-fold lower than docosahexaenoic acid (DHA), at least partly, because EPA is rapidly β-oxidized and lost from brain phospholipids. Therefore, we examined if β-oxidation was necessary for maintaining low EPA levels by inhibiting β-oxidation with methyl palmoxirate (MEP). Furthermore, because other metabolic differences between DHA and EPA may also contribute to their vastly different levels, this study aimed to quantify the incorporation and turnover of DHA and EPA into brain phospholipids. Fifteen-week-old rats were subjected to vehicle or MEP prior to a 5 min intravenous infusion of 14C-palmitate, 14C-DHA, or 14C-EPA. MEP reduced the radioactivity of brain aqueous fractions for 14C-palmitate-, 14C-EPA-, and 14C-DHA-infused rats by 74, 54, and 23%, respectively; while it increased the net rate of incorporation of plasma unesterified palmitate into choline glycerophospholipids and phosphatidylinositol and EPA into ethanolamine glycerophospholipids and phosphatidylserine. MEP also increased the synthesis of n-3 docosapentaenoic acid (n-3 DPA) from EPA. Moreover, the recycling of EPA into brain phospholipids was 154-fold lower than DHA. Therefore, the low levels of EPA in the brain are maintained by multiple redundant pathways including β-oxidation, decreased incorporation from plasma unesterified FA pool, elongation/desaturation to n-3 DPA, and lower recycling within brain phospholipids.http://www.sciencedirect.com/science/article/pii/S0022227520351312incorporationturnoverkineticsβ-oxidation |
| spellingShingle | Chuck T. Chen Anthony F. Domenichiello Marc-Olivier Trépanier Zhen Liu Mojgan Masoodi Richard P. Bazinet The low levels of eicosapentaenoic acid in rat brain phospholipids are maintained via multiple redundant mechanisms Journal of Lipid Research incorporation turnover kinetics β-oxidation |
| title | The low levels of eicosapentaenoic acid in rat brain phospholipids are maintained via multiple redundant mechanisms |
| title_full | The low levels of eicosapentaenoic acid in rat brain phospholipids are maintained via multiple redundant mechanisms |
| title_fullStr | The low levels of eicosapentaenoic acid in rat brain phospholipids are maintained via multiple redundant mechanisms |
| title_full_unstemmed | The low levels of eicosapentaenoic acid in rat brain phospholipids are maintained via multiple redundant mechanisms |
| title_short | The low levels of eicosapentaenoic acid in rat brain phospholipids are maintained via multiple redundant mechanisms |
| title_sort | low levels of eicosapentaenoic acid in rat brain phospholipids are maintained via multiple redundant mechanisms |
| topic | incorporation turnover kinetics β-oxidation |
| url | http://www.sciencedirect.com/science/article/pii/S0022227520351312 |
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