Age dependent incorporation of 14C-DHA into rat brain and body tissues after dosing various 14C-DHA-esters

IntroductionThe omega-3 fatty acid docosahexaenoic acid (DHA) accounts for 10% of fatty acids in human brain and is critical for neuronal function and brain development. Mechanisms of transport, accumulation and conservation of DHA in the brain are unclear. The objective of the study was to quantify the age dependent DHA incorporation into the brain of 2-, 4- or 10-week-old rats after a bolus dose of different DHA-esters.MethodsRats were gavaged with 14C-DHA-TAG, 14C-DHA-PL or 14C-DHA-TAG+PL at 2 mg DHA/kg BW. After 24 h the distribution of radioactivity in body and brain regions was determined using quantitative whole body autoradiography (QWBA). Radiolabeled compounds were extracted from the brains to determine the identity of the radiolabeled compounds.ResultsAccumulation of orally ingested 14C-DHA in rat brain was less than 1% of the dose and decreased with age. Ester specific differences were seen only in 10-week-old rats, where oral 14C-DHA-PL delivered a 2-fold higher accretion of radioactivity in the brain.ConclusionsLess than 1% of a dietary achievable DHA dose reached the rat brain within 24 h. Optimal efficacy of DHA-PL may occur in older age groups.