Antagonism of Selenium and Cadmium Pretreatments to Subsequent Embryotoxic Doses of Mercury and Cadmium in Fish Embryos

摘要

Research was carried out to assess the protective role of selenium (Se) and cadmium (Cd) pre-exposures to fish embryos in attentuating toxic doses of mercury (Hg) and Cd. Experiments were carried out under laboratory-controlled conditions using Japanese ricefish (Oryzias latipes). Results indicated a protective role of Se pretreatment against Hg and Cd exposures in fish embryos once the liver has developed. In addition, pretreatment of post-liver embryos with sublethal concentrations of Cd also affords protection against subsequent potentially lethal Cd exposures. These antagonistic interactions, however, appear not to occur prior to liver development. The results confirm the hypothesis that, during early embryonic development, the protective effects of Se or Cd will be nonexistant or minimal.