Metherel Adam H, Kitson Alex P, Domenichiello Anthony F, Lacombe R J Scott, Hopperton Kathryn E, Trépanier Marc-Olivier, Alashmali Shoug M, Lin Lin, Bazinet Richard P
Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, 150 College St., Toronto, Ontario, Canada, M5S 3E2.
Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, 150 College St., Toronto, Ontario, Canada, M5S 3E2.
J Nutr Biochem. 2017 Aug;46:143-150. doi: 10.1016/j.jnutbio.2017.05.011. Epub 2017 Jun 1.
Maternal docosahexaenoic acid (DHA, 22:6n-3) supplies the developing fetus during pregnancy; however, the mechanisms are unclear. We utilized pregnant rats to determine rates of DHA accretion, tissue unesterified DHA uptake and whole-body DHA synthesis-secretion. Female rats maintained on a DHA-free, 2% α-linolenic acid diet were either:1) sacrificed at 56 days for baseline measures, 2) mated and sacrificed at 14-18 days of pregnancy or 3) or sacrificed at 14-18 days as age-matched virgin controls. Maternal brain, adipose, liver and whole body fatty acid concentrations was determined for balance analysis, and kinetic modeling was used to determine brain and liver plasma unesterified DHA uptake and whole-body DHA synthesis-secretion rates. Total liver DHA was significantly higher in pregnant (95±5 μmol) versus non-pregnant (49±5) rats with no differences in whole-body DHA synthesis-secretion rates. However, liver uptake of plasma unesterified DHA was 3.8-fold higher in pregnant animals compared to non-pregnant controls, and periuterine adipose DHA was lower in pregnant (0.89±0.09 μmol/g) versus non-pregnant (1.26±0.06) rats. In conclusion, higher liver DHA accretion during pregnancy appears to be driven by higher unesterified DHA uptake, potentially via DHA mobilization from periuterine adipose for delivery to the fetus during the brain growth spurt.
孕期母体二十二碳六烯酸（DHA，22:6n - 3）为发育中的胎儿提供营养；然而，其机制尚不清楚。我们利用怀孕大鼠来确定DHA的蓄积率、组织中非酯化DHA的摄取以及全身DHA的合成 - 分泌情况。以不含DHA、含2%α - 亚麻酸的饮食喂养的雌性大鼠分为以下几组：1）在第56天处死以获取基线测量值；2）交配后在怀孕第14 - 18天处死；或3）在第14 - 18天处死作为年龄匹配的未孕对照。测定母体大脑、脂肪、肝脏和全身的脂肪酸浓度以进行平衡分析，并使用动力学模型来确定大脑和肝脏血浆中非酯化DHA的摄取以及全身DHA的合成 - 分泌率。怀孕大鼠（95±5 μmol）肝脏中的总DHA含量显著高于未孕大鼠（49±5 μmol），而全身DHA的合成 - 分泌率并无差异。然而，与未孕对照相比，怀孕动物肝脏对血浆中非酯化DHA的摄取高出3.8倍，并且怀孕大鼠子宫周围脂肪中的DHA含量（0.89±0.09 μmol/g）低于未孕大鼠（1.26±0.06 μmol/g）。总之，孕期肝脏中较高的DHA蓄积似乎是由较高的非酯化DHA摄取所驱动，这可能是通过子宫周围脂肪中DHA的动员，以便在脑发育快速期将其输送给胎儿。
