Aschner Michael, Dorman David C
Department of Pediatrics, Pharmacology, and the Kennedy Center for Research on Human Development, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
Toxicol Rev. 2006;25(3):147-54. doi: 10.2165/00139709-200625030-00002.
Manganese is an essential mineral that is found at low levels in virtually all diets. Manganese ingestion represents the principal route of human exposure, although inhalation also occurs, predominantly in occupational cohorts. Regardless of intake, animals generally maintain stable tissue manganese levels as a result of homeostatic mechanisms that tightly regulate the absorption and excretion of this metal. However, high-dose exposures are associated with increased tissue manganese levels, causing adverse neurological, reproductive and respiratory effects. In humans, manganese-induced neurotoxicity is associated with a motor dysfunction syndrome, commonly referred to as manganism or Parkinsonism, which is of paramount concern and is considered to be one of the most sensitive endpoints. This article focuses on the dosimetry of manganese with special focus on transport mechanisms of manganese into the CNS. It is not intended to be an exhaustive review of the manganese literature; rather it aims to provide a useful synopsis of contemporary studies from which the reader may progress to other research citations as desired. Specific emphasis is directed towards recent published literature on manganese transporters' systemic distribution of manganese upon inhalation exposure as well as the utility of magnetic resonance imaging in quantifying brain manganese distribution.
锰是一种必需的矿物质，几乎在所有饮食中含量都很低。摄入锰是人类接触锰的主要途径，不过吸入也会发生，主要发生在职业人群中。无论摄入量如何，由于体内平衡机制严格调节这种金属的吸收和排泄，动物通常能维持稳定的组织锰水平。然而，高剂量接触会导致组织锰水平升高，从而引起不良的神经、生殖和呼吸影响。在人类中，锰诱导的神经毒性与一种运动功能障碍综合征有关，通常称为锰中毒或帕金森症，这是最为关注的问题，并且被认为是最敏感的终点之一。本文重点关注锰的剂量测定，特别关注锰进入中枢神经系统的转运机制。它并非对锰相关文献的详尽综述；相反，其目的是提供当代研究的有用概要，读者可根据需要进一步查阅其他研究引用文献。特别强调了近期发表的关于锰转运体、吸入暴露后锰的全身分布以及磁共振成像在量化脑锰分布方面的应用的文献。
