Friberg L, Mottet N K
Department of Environmental Hygiene, Karolinska Institute, Stockholm, Sweden.
Biol Trace Elem Res. 1989 Jul-Sep;21:201-6. doi: 10.1007/BF02917253.
Differences in metabolism between different mercury species are well recognized. Conclusions that only a minor demethylation of methylmercury takes place in the brain are based primarily on results from short term studies. Results from a number of studies on humans exposed for many years to methylmercury have shown high concentrations of inorganic mercury in the brain in relation to total mercury. Similar evidence is available from studies on monkeys exposed for several years to methylmercury. The results indicate that a significant accumulation of inorganic mercury takes place with time despite the fact that the demethylation rate is slow. Differences in biological halftimes between different mercury species will explain the results. Some data do still need confirmation using different analytical methods. There is reason to believe that the one-compartment model for methyl mercury cannot be used without reservations. Inorganic mercury has a complicated metabolism. After exposure to metallic mercury vapor, inorganic mercury, probably bound to selenium, accumulates in the brain. A fraction of the mercury is excreted, with a long biological halftime. Studies on rats and monkeys indicate that inorganic mercury penetrates the blood-brain barrier only to a very limited extent.
不同汞物种之间的代谢差异已得到充分认识。关于甲基汞在大脑中仅发生少量脱甲基作用的结论主要基于短期研究结果。多项针对长期接触甲基汞的人类的研究结果表明，大脑中无机汞的浓度相对于总汞含量较高。对接触甲基汞数年的猴子的研究也有类似证据。结果表明，尽管脱甲基速率缓慢，但随着时间的推移，无机汞会大量积累。不同汞物种之间生物半衰期的差异可以解释这些结果。仍有一些数据需要使用不同的分析方法进行确认。有理由相信，甲基汞的单室模型不能毫无保留地使用。无机汞的代谢很复杂。接触金属汞蒸气后，无机汞可能与硒结合，在大脑中积累。一部分汞会排出，生物半衰期很长。对大鼠和猴子的研究表明，无机汞仅在非常有限的程度上穿透血脑屏障。
