Effect of kidney damage on the mobilisation of mercury by thiol-complexing agents.

ABSTRACT Mobilisation of mercury by thiol-complexing agents is the accepted treatment for chronic mercury intoxication. The success of such treatment is judged by the urinary excretion of mercury which might be modified by existing kidney damage caused either by the mercury itself or by other factors. In the present work the ability of three thiol-complexing agents, D-penicillamine, N-acetyl-D, L-penicillamine, and 2,3-dimercaptosuccinic acid (DMSA) to remove mercury from a damaged kidney and to increase the urinary excretion of mercury were studied. Kidney damage was induced by the injection of 20 mg/kg sodium chromate three days before the injection of 2·5 μmoles/kg HgCl or three and seven days before the administration of a similar dose of mercury complexed with D-penicillamine. It was shown that both renal uptake and urinary excretion of mercury were decreased in animals with damaged kidneys. This effect lessened with time between the induction of damage and the injection of mercury-penicillaminate. Each of the three chelating agents was given 48 and 54 hours after the administration of HgCl in equivalent (400 μmoles/kg) doses. All were able to remove mercury from the kidneys, but DMSA was far the most effective and only DMSA increased the urinary excretion of mercury. The amount of mercury removed from the kidneys by the chelators was less in animals with renal damage than in controls, but the difference was insignificant if renal mercury depletion was related to the initial renal mercury content.