Université de Bordeaux, CNRS UMR 5805, Station Marine d'Arcachon, place du Docteur Peyneau, Arcachon, 33120, France; Present address: Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), 5 avenue des Hauts-Fourneaux, Esch-sur-Alzette, Luxembourg.
National Institute for Minamata Disease, Pathology Section, Department of Basic Medical Sciences, 4058-18 Hama, Minamata, Kumamoto, 867-0008, Japan.
Food Chem Toxicol. 2018 Dec;122:11-20. doi: 10.1016/j.fct.2018.09.066. Epub 2018 Sep 29.
Methylmercury (MeHg) taken up through fish consumption can be transferred from the mother to the fetus during pregnancy. In the present study, pregnant rat mothers were contaminated with environmentally relevant doses of 36 and 76 ng MeHg/g of food using diets containing naturally mercury-containing fish. Young female rats fed with fish-containing food after weaning showed decreased locomotion in Y maze for accumulated concentrations in brain as low as 75 ng Hg/g dry weight (15 ng Hg/g wet weight). Young female rats fed the control diet after weaning yet borne by mothers fed the diet containing 76 ng MeHg/g, presented a 58% reduced activity in the open-field labyrinth, meaning that the maternal exposure to fish-containing food exerted an effect in utero that lasted several weeks after birth. Newborns were protected against Hg exposure by the placental barrier since in newborns from mothers fed the diet containing 76 ng MeHg/g of food, the concentrations of Hg in brain, kidney, liver and skeletal muscles represented 12, 3, 21 and 18% of those of their mother's tissues, respectively. These results suggest the existence, at least in rats, of a threshold level in terms of MeHg exposure above which the placental barrier collapses.
甲基汞（MeHg）通过鱼类摄入后，可在怀孕期间从母体转移到胎儿体内。在本研究中，用含有天然含汞鱼类的食物喂养怀孕的大鼠，使大鼠母亲受到环境相关剂量的 36 和 76ng MeHg/g 食物污染。在断乳后食用含鱼食物的雌性幼鼠，在大脑中汞的浓度低至 75ng Hg/g 干重（15ng Hg/g 湿重）时，其在 Y 迷宫中的运动能力下降。在断乳后食用对照饮食但由食用含 76ng MeHg/g 食物的母亲孕育的雌性幼鼠，在开放式迷宫中的活动减少了 58%，这意味着母体暴露于含鱼食物的影响在出生后持续了数周。胎盘屏障使新生儿免受汞暴露的影响，因为在食用含 76ng MeHg/g 食物的母亲的新生儿中，大脑、肾脏、肝脏和骨骼肌中的汞浓度分别为其母体组织的 12%、3%、21%和 18%。这些结果表明，至少在大鼠中，存在一个胎盘屏障崩溃的甲基汞暴露阈值水平。
