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


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 





methyl mercury


ethyl mercury



polymorphonuclear leukocyte


superoxide anion


hydrogen peroxide


hydroxyl radical


singlet oxygen


hypochlorous acid




phorbol myristate acetate


Eagle's minimum essential medium


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Dallegri F, Patrone F, Bonvini E, Gahrton G, Holm G, Sacchetti C (1983) Ox erythrocyte cytotoxicity by phorbol myristate acetate-activated human neutrophils. Scand J Immunol 17: 109–114PubMedGoogle Scholar
  2. Horiuchi S, Takata K, Morino Y (1985) Characterization of a membraneassociated receptor from rat sinusoidal liver cells that binds formaldehyde-treated serum albumin. J Biol Chem 260: 475–481PubMedGoogle Scholar
  3. Jong EC, Henderson WR, Klebanoff SJ (1980) Bactericidal activity of eosinophil peroxidase. J Immunol 124: 1378–1382PubMedGoogle Scholar
  4. Klebanoff SJ (1980) Oxygen metabolism and the toxic properties of phagocytes. Ann Int Med 93: 480–489PubMedGoogle Scholar
  5. Konishi T, Takahashi H (1983) Direct determination of inorganic mercury in biological materials after alkali digestion and amalgamation. Analyst 108: 827–834CrossRefPubMedGoogle Scholar
  6. Lee KC, Shiozawa C, Shaw A, Diener E (1976) Requirement for accessory cells in the antibody response to T cell-independent antigens in vitro. Eur J Immunol 6: 63–68PubMedGoogle Scholar
  7. Parker CW (1984) Mediators: release and function. In: Paul WE (ed) Fundamental immunology. Raven Press, New York, pp 697–747Google Scholar
  8. Pick E, Keisari Y (1980) A simple colorimetric method for the measurement of hydrogen peroxide produced by cells in culture. J Immunol Methods 38: 161–170CrossRefPubMedGoogle Scholar
  9. Sasada M, Kubo A, Nishimura T, Kakita T, Moriguchi T, Yamamoto K, Uchino H (1987) Candidacidal activity of monocyte-derived human macrophages: relationship between Candida killing and oxygen radical generation by human macrophages. J Leukoc Biol 41: 289–294PubMedGoogle Scholar
  10. Suda I, Takahashi H (1986) Enhanced and inhibited biotransformation of methyl mercury in the rat spleen. Toxicol Appl Pharmacol 82: 45–52CrossRefPubMedGoogle Scholar
  11. Suda I, Takahashi H (1990) Effect of reticuloendothelial system blockade on the biotransformation of methyl mercury in the rat. Bull Environ Contam Toxicol 44: 609–615CrossRefPubMedGoogle Scholar
  12. Suda I, Takahashi H (1992) Degradation of methyl and ethyl mercury into inorganic mercury by other reactive oxygen species besides hydroxyl radical. Arch Toxicol 66: 34–39CrossRefPubMedGoogle Scholar
  13. Suda I, Totoki S, Konishi T, Takahashi H (1990) Biotransformation of alkyl mercury by active oxygen producing systems. Comprehensive Studies on Minamata Disease 16 [Suppl]: 39–49Google Scholar
  14. Suda I, Totoki S, Takahashi H (1991) Degradation of methyl and ethyl mercury into inorganic mercury by oxygen free radical-producing systems: involvement of hydroxyl radical. Arch Toxicol 65: 129–135CrossRefPubMedGoogle Scholar
  15. Uchida T, Ju ST, Fay A, Liu YN, Dorf ME (1985) Functional analysis of macrophage hybridomas: I. production and initial characterization J Immunol 134: 772–778PubMedGoogle Scholar
  16. Weiss SJ, Klein R, Slivka A, Wei M (1982) Chlorination of taurine by human neutrophils: evidence for hypochlorous acid generation J Clin Invest 70: 598–607PubMedGoogle Scholar

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

Personalised recommendations