Brain phospholipid arachidonic acid half-lives are not altered following 15 weeks of N-3 polyunsaturated fatty acid adequate or deprived diet.
Previous studies have infused radiolabeled arachidonic acid (AA) into rat brains and followed AA esterification into phospholipids for up to 24 h; however, the half-life of AA in rat brain phospholipids is unknown. Eighteen day old rats were fed either an n-3 PUFA adequate or deprived diet for 15 weeks. Following the 15 weeks, 40 microCi of [(3)H] AA was injected intracerebroventricularly into the right lateral ventricle using stereotaxic surgery and returned to their dietary treatment. From 4-120 days after [(3)H] AA administration, brains were collected for chemical analyses. The half-life of AA in rat brain phospholipids was 44 +/- 4 days for the n-3 PUFA adequate group and 46 +/- 4 days for the n-3 PUFA deprived group, which closely approximates the predicted half-life previously reported, based on the rate of entry from the plasma unesterified pool, suggesting the plasma unesterified pool is a major contributor to brain uptake of AA. Furthermore, unlike a previous report in which the half-life of brain phospholipid docosahexaenoic acid (DHA) was increased in n-3 PUFA deprived rats, n-3 PUFA deprivation did not significantly alter the AA half-life, suggesting different mechanisms exist to maintain brain concentrations of AA and DHA.
Green
Joshua T
JT
Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Canada.
Liu
Zhen
Z
Bazinet
Richard P
RP
D000818:Animals; D016718:Arachidonic Acid / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism*; D001835:Body Weight / Q000187:drug effects; D001921:Brain / Q000187:drug effects* / Q000378:metabolism*; D004042:Dietary Fats, Unsaturated / Q000494:pharmacology*; D004951:Esterification; D015525:Fatty Acids, Omega-3 / Q000494:pharmacology*; D006207:Half-Life; D007267:Injections; D008297:Male; D010743:Phospholipids / Q000378:metabolism*; D011849:Radioactive Tracers; D051381:Rats; D013997:Time Factors
D004042:Dietary Fats, Unsaturated; D015525:Fatty Acids, Omega-3; D010743:Phospholipids; D011849:Radioactive Tracers; D016718:Arachidonic Acid