Determination of the Low Hg Accumulation in Rabbitfish (Siganus canaliculatus) by Various Elimination Pathways: Simulation by a Physiologically Based Pharmacokinetic Model
Determination of the Low Hg Accumulation in Rabbitfish (Siganus canaliculatus) by Various Elimination Pathways: Simulation by a Physiologically Based Pharmacokinetic Model
复制标题
通过各种消除途径测定兔鱼 (Siganus canaliculatus) 中的低汞积累：通过基于生理的药代动力学模型进行模拟
DOI：
10.1021/acs.est.0c00772
复制
发表时间：
2020
影响因子：
11.4
通讯作者：
Wang Wen-Xiong
中科院分区：
文献类型：
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作者：
Wang Xun;Wang Wen-Xiong
鱼类体内的汞对人类健康构成巨大威胁。食用低汞含量的鱼类（如兔鱼、小管Siganus canaliculatus）可能是平衡营养益处和汞暴露的一种可能解决方案。然而，兔鱼体内低汞积累的潜在机制尚不清楚。本研究通过构建基于生理的药代动力学（PBPK）模型，定量描述了不同暴露途径下兔鱼体内无机汞（II）和甲基汞（MeHg）的处置。结果表明，兔鱼体内汞含量低的主要原因是对水中汞(II)-、饲料汞(II)-和甲基汞暴露鱼的有效消除（估计速率常数分别为0.060、0.065和0.020 d - 1）。通过对Hg消除量化的可能途径,我们的研究显示胆道加上粪便排泄发挥了重要作用消除饮食Hg。尽管MeHg胆汁排泄率显著(6.8±2.2 d 1)和排出量每天可达到790 ng,大多数MeHg胆汁被小肠吸收和传输通过肝肠循环回到肝脏,导致长时间的保留时间在鱼的身体。此外，在水暴露后，鳃部排泄主导了汞（II）的消除，这表明在不同的暴露情况下，消除途径会发生灵活的变化。本研究为兔鱼维持低汞水平所采取的独特策略提供了重要的认识。
Mercury (Hg) in fish poses a great threat to human health. Consumption of low-Hg-level fish species (e.g., rabbitfish,Siganus canaliculatus) could be one possible solution to balance the nutrient benefits and Hg exposure. However, the underlying mechanisms for the low Hg accumulation in rabbitfish remain unclear. This study quantitatively described the disposition of inorganic Hg(II) and methylmercury (MeHg) in rabbitfish under different exposure routes by constructing a physiologically based pharmacokinetic (PBPK) model. The results strongly suggested that effective elimination (estimated rate constant of 0.060, 0.065, and 0.020 d–1for waterborne Hg(II)-, dietary Hg(II)-, and MeHg-exposed fish, respectively) was the main reason for the low Hg accumulation in rabbitfish. By quantifying the possible pathways for Hg elimination, our study revealed that biliary coupled with fecal excretion played an important role in the elimination of dietary Hg. Although the biliary excretion rate for MeHg was remarkable (6.8 ± 2.2 d–1) and the excreted amount per day could reach up to 790 ng, most of the MeHg in the bile was reabsorbed by the intestine and transferred back to the liver through enterohepatic circulation, leading to a prolonged retention time in the fish body. Moreover, branchial excretion dominated the Hg(II) elimination following aqueous exposure, suggesting a flexible alteration on elimination pathways against different exposure scenarios. The present study provided important understanding of the unique strategies adopted by rabbitfish to maintain the low Hg levels.