Effects of several dithiocarbamates on tissue distribution and excretion of inorganic mercury in rats.

Abstract

The effects of various chelating agents, sodium N-benzyl-D-glucamine dithiocarbamate (BGD), sodium N-p-methylbenzyl-D-glucamine dithiocarbamate (MBGD), sodium N-p-hydroxymethylbenzyl-D-glucamine dithiocarbamate (HBGD), and N-p-carboxybenzyl-D-glucamine dithiocarbamate (CBGD), which were newly synthesized, and sodium N-methyl-D-glucamine dithiocarbamate (MGD), on the distribution and excretion of inorganic mercury were compared in rats exposed to HgCl2. Rats were injected i.p. with 203HgCl2 (300 micrograms of Hg and 74 kBq of 203Hg/kg) and 30 min or 24 h later, they were injected with a dithiocarbamate (1200 mumol/kg). At 30 min after mercury administration, BGD and MBGD significantly enhanced the biliary excretion of mercury, while CBGD, MGD, and HBGD enhanced the urinary excretion of mercury to a small extent. At 24 h after mercury injection, BGD was the most effective on the biliary excretion of the metal, while MGD and HBGD significantly enhanced the urinary excretion of the metal. All of these dithiocarbamates were effective in mobilizing mercury from the kidney at 30 min after mercury treatment. At 24 h after mercury treatment, HBGD and BGD effectively depressed mercury content in the kidney. These results show that the injection of BGD and HBGD at both 30 min and 24 h after mercury treatment can much more effectively mobilize mercury from the kidney without redistribution of mercury to other tissues, such as brain, heart, and lung, when compared with injection of other chelating agents. The pattern of mobilization and excretion of mercury following treatment with each chelating agent was related to the organic/aqueous partition coefficient of each dithiocarbamate-mercury complex.