Dept. of Nutritional Sciences, Cornell University, Ithaca, NY, USA.
Dept. of Obstetrics & Gynecology, University of Rochester School of Medicine & Dentistry, Rochester, NY, USA; Dept. of Pathology and Clinical Laboratory Medicine, University of Rochester School of Medicine & Dentistry, Rochester, NY, USA; Dept. of Environmental Medicine, University of Rochester School of Medicine & Dentistry, Rochester, NY, USA.
Environ Res. 2017 Oct;158:553-565. doi: 10.1016/j.envres.2017.07.008. Epub 2017 Jul 14.
The placenta is responsible for the exchange of nutrients and for preventing harmful compounds from entering the fetal circulation. With increasing industrialization, exposures to commercial and toxic metals become a concern for both pregnant women and those planning a pregnancy. The understanding of transport mechanisms and pharmacokinetics for most inorganic elements is incomplete and limited to normal term deliveries.
To obtain novel data on 46 inorganic elements in placentae from two high-risk obstetric populations, women carrying multiples and adolescents carrying singletons, evaluating differences, if present, and identifying predictors of placental content.
Placental tissue was collected from adolescents carrying singletons and adults carrying multiples. Elemental content was analyzed using inductively coupled plasma-mass spectrometry (ICP-MS). Multivariate regression and factor analyses were used.
With the exception of Au and Pt, almost all placentae contained quantifiable concentrations of each element analyzed. All placentae contained the essential elements Ca, Fe, Mg, Se and Zn, which clustered together onto the same factor. Most elements were higher in placentae from women carrying multiples. Differences in placental content disappeared after adjusting for maternal age. Rare earth elements (REEs) clustered together and remained higher in the multiples even after adjusting for maternal age.
Human placentae contain a wide range of elements, including REEs. Ranges differed considerably between cohorts. Elements with similar chemical properties, like REEs or nutritionally essential elements, clustered together. Maternal age, and therefore longer environmental exposure, was significantly associated with elevated element concentrations in the placenta. Placental concentrations of several metals that are known to be nutritionally essential (e.g., Fe, Ca, Mg, and Zn) did not differ significantly between cohorts, suggesting tight regulation, whereas concentrations of environmental contaminants differed significantly between groups, even after adjusting for maternal age.
胎盘负责营养物质的交换，并防止有害物质进入胎儿循环。随着工业化的发展，商业和有毒金属的暴露对孕妇和计划怀孕的人都构成了担忧。对于大多数无机元素的转运机制和药代动力学的了解并不完整，仅限于正常足月分娩。
从两个高危产科人群（怀多胞胎的妇女和怀单胎的青少年）中获得 46 种无机元素在胎盘中的新数据，评估是否存在差异，并确定胎盘含量的预测因素。
采集怀单胎的青少年和怀多胎的成年人的胎盘组织。使用电感耦合等离子体质谱法（ICP-MS）分析元素含量。采用多元回归和因子分析。
除了 Au 和 Pt 之外，几乎所有胎盘都含有可量化浓度的每种分析元素。所有胎盘都含有必需元素 Ca、Fe、Mg、Se 和 Zn，它们聚集在同一因子上。大多数元素在怀多胎的妇女的胎盘中的含量更高。调整母亲年龄后，胎盘含量的差异消失。调整母亲年龄后，稀土元素（REEs）仍聚集在一起，且在多胎妊娠妇女的胎盘中的含量更高。
人类胎盘含有广泛的元素，包括 REEs。队列之间的范围差异很大。具有相似化学性质的元素，如 REEs 或营养必需元素，聚集在一起。母亲年龄，即更长时间的环境暴露，与胎盘内元素浓度升高显著相关。几种已知是营养必需的金属（如 Fe、Ca、Mg 和 Zn）的胎盘浓度在队列之间没有显著差异，表明其受到严格调节，而环境污染物的浓度在组间存在显著差异，即使在调整母亲年龄后也是如此。
