Inhibitory effect of α-tocopherol on methylmercury-induced oxidative steress

  • Taro Yamashita
  • Yukio Ando
  • Masaaki Nakamura
  • Konen Obayashi
  • Hisayasu Terazaki
  • Katsuki Haraoka
  • Sun Xu Guo
  • Mitsuharu Ueda
  • Makoto Uchino
Original Article

DOI: 10.1007/BF02898069

Cite this article as:
Yamashita, T., Ando, Y., Nakamura, M. et al. Environ Health Prev Med (2004) 9: 111. doi:10.1007/BF02898069

Abstract

Objectives

The present study investigated the involvement of oxidative stress in the degeneration of the cerebellum during methylmercury (MeHg) intoxication and the protective effect of α-tocopherol (Vit E) against MeHg toxicity.

Methods

After 5 mg/kg of MeHg was administered to Wistar rats for 12 consecutive days, the cerebellum were examined histopathologically. In addition, the same amount of MeHg was administered to 3 different groups of Wistar rats: rats with a Vit E-deficient diet, rats fed 150 mg/kg of Vit E for 20 consecutive days after initial MeHg administration, and rats with an ordinary diet.

Results

Positive immunoreactivity against anti-hydroxynonenal (HNE), a marker of lipid peroxidation, was observed in the cerebellum after MeHg administration. Levels of thiobarbituric acid reactive substance (TBARS), another marker of lipid peroxidation, and those of protein carbonyl, a biomarker for protein oxidation, increased after MeHg administration. In the rats with MeHg and a Vit E-deficient diet, mortality and prevalence of piloerection significantly increased, and in the rats with MeHg and Vit E, mortality, piloerection, retracted and crossed hind leg, and ataxic gait significantly decreased, compared with the rats with MeHg alone. The levels of NO2 and NO3 in the serum significantly increased in the rats with MeHg alone 14 days after the initial MeHg administration, but were significantly suppressed by Vit E administration.

Conclusions

Oxidative stress, especially lipid peroxidation, may play an important role in the cerebellar degeneration process during MeHg intoxication and Vit E may play a protective role against MeHg toxicity as an effective antioxidant.

Key words

methylmercury oxidative stress vitamin E cerebellar degeneration lipid peroxidation 

Copyright information

© Japanese Society of Hygiene 2004

Authors and Affiliations

  • Taro Yamashita
    • 1
  • Yukio Ando
    • 3
  • Masaaki Nakamura
    • 3
  • Konen Obayashi
    • 1
  • Hisayasu Terazaki
    • 2
  • Katsuki Haraoka
    • 2
  • Sun Xu Guo
    • 3
  • Mitsuharu Ueda
    • 1
  • Makoto Uchino
    • 1
  1. 1.Department of Neurology, Graduate School of Medical SciencesKumamoto UniversityKumamotoJapan
  2. 2.Department of Gastroenterology and Hepatology, Graduate School of Medical SciencesKumamoto UniversityKumamotoJapan
  3. 3.Department of Diagnostic Medicine, Graduate School of Medical SciencesKumamoto UniversityKumamotoJapan

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