Protective effect of sodium molybdate on the acute toxicity of mercuric chloride. V. Enhancement of renal regeneration after exposure to HgCl2.

Pretreatment with Na2MoO4 protected rats from HgCl2-induced decreases in the renal concentration of amino acids, RNA, DNA, ATP and dry matter. It also reduced the mercury-induced increases in renal water, Ca and serum creatinine. Ma2MoO4 considerably elevated the RNA/DNA ratio in the renal cortex after treatment with HgCl2. In addition, subcellular distribution of mercury was markedly altered by pretreatment with Na2MoO4, specifically Na2MoO4 pretreatment decreased the mercury content in the particulate fractions such as the nuclei and mitochondria while increasing the mercury content of the cytosol. Sephadex G-75 gel filtration showed that the increase in mercury content in the cytosol of Na2MoO4-pretreated rats is due to an increase in the metal content of a metallothionein-like fraction. These results suggest that Na2MoO4-pretreatment protects against HgCl2 renal toxicity by stimulating mercury-mediated metallothionein induction in the renal cortex and renal regenerative processes.