Distribution of mercury in metallothionein-null mice after exposure to mercury vapor: amount of metallothionein isoform does not affect accumulation of mercury in the brain

  • Yasutake Akira
    Kumamoto University Graduate School of Science and Technology
  • Yoshida Minoru
    Fuculty of Human Health Sciences, Hachinohe University
  • Honda Akiko
    Laboratory of Pharmaceutical Health Sciences, School of Pharmacy, Aichi Gakuin University
  • Watanabe Chiho
    Department of Human Ecology, Graduate School of Medicine, University of Tokyo
  • Satoh Masahiko
    Laboratory of Pharmaceutical Health Sciences, School of Pharmacy, Aichi Gakuin University

Search this article

Abstract

To examine the contribution of metallothionein (MT) to mercury accumulation in mouse tissues, 129 strain female mice and MT null mice were exposed to metallic mercury vapor at a sub-toxic level, and Hg levels in the brain, kidney and liver were determined on 1, 3 and 7 days after the exposure. After exposure to mercury vapor, significant Hg accumulation was observed in the brains of wild-type and MT-I/II null and MT-III null mice, as well as in the liver and kidneys. No strain difference was observed in the tissue Hg accumulations 24 hr after the exposure except for the kidneys, where the highest accumulation was found in MT-III null mice. Although the brains of MT-III null mice showed slightly higher Hg accumulation than the other two strains, no significant difference was observed except in the cerebrum on Day 7. Gel chromatograms of cerebrum soluble fractions revealed that a significant amount of Hg existed as an MT-bound form in all the mouse strains. On the other hand, MT-bound Hg was found as a minor fraction in soluble fractions of the kidneys and livers in wild-type and MT-III null mice. Despite a significant strain difference in total MT levels in the cerebrum, there was no difference among the three strains in the amount of Hg accumulated in the cerebrum and its distribution rates in MT fractions. The present study demonstrated that brain uptake of Hg0 and its accumulation as Hg2+ did not depend on the amount of MT isoform in the tissue, at least in the early phase.

Journal

References(27)*help

See more

Details 詳細情報について

Report a problem

Back to top