Archives of Toxicology

, Volume 66, Issue 1, pp 40–44 | Cite as

Degradation of methyl and ethyl mercury into inorganic mercury by various phagocytic cells

  • Ikuo Suda
  • Shinji Totoki
  • Tetsuya Uchida
  • Hitoshi Takahashi
Original Investigations

Abstract

In connection with the dealkylation of methyl mercury (MeHg) and ethyl Hg (EtHg) with reactive oxygen-producing systems, we examined the ability of phagocytic cells to degrade MeHg or EtHg into inorganic mercury in vitro by collecting them from blood or peritoneal cavity of several species of animal. EtHg was readily degraded by human polymorphonuclear leukocytes (PMN), rat PMN, guinea-pig PMN, rabbit PMN, guinea-pig macrophages (Mφ), human monocytes and guinea-pig eosinophils. In contrast, rat hepatocytes and the Mφ hybridoma clone 39 cells were weaker in their degrading ability. Degradation of MeHg by these cells was always much weaker than EtHg, under identical conditions; how-ever, by increasing the cell numbers, MeHg was appreciably degraded by human PMN, rat PMN and rabbit PMN. The reactive oxygen species mainly responsible for alkyl Hg degradation seemed to be hydroxyl radicals produced by Mφ, and hypochlorous acid produced by PMN, monocytes and eosinophils. It was also suggested that the degradation of alkyl Hg by these cells might be an intraphagosomal event.

Key words

Methyl mercury Ethyl mercury Biotrans-formation Reactive oxygen Phagocytic cells 

Abbreviations

Hg

mercury

MeHg

methyl mercury

EtHg

ethyl mercury

macrophage

PMN

polymorphonuclear leukocyte

O2

superoxide anion

H2O2

hydrogen peroxide

OH

hydroxyl radical

1O2

singlet oxygen

HOCl

hypochlorous acid

MPO

myeloperoxidase

PMA

phorbol myristate acetate

Eagle-MEM

Eagle's minimum essential medium

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Copyright information

© Springer-Verlag 1992

Authors and Affiliations

  • Ikuo Suda
    • 1
  • Shinji Totoki
    • 1
  • Tetsuya Uchida
    • 2
  • Hitoshi Takahashi
    • 1
  1. 1.Department of Pharmacology, Institute for Medical ImmunologyKumamoto University Medical SchoolKumamotoJapan
  2. 2.Department of General Biologics ControlNational Institute of HealthTokyoJapan

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