The effect of some chelating agents on the biliary and urinary excretion of manganese in rats.

The biliary excretion of manganese, in rats which have been loaded with manganese via their drinking water, can be significantly enhanced by the administration of the chelating agents: desferrioxamine (DSF), sodium bis(hydroxyethyl) dithiocarbamate (DEDTC), and sodium isonipecotamidedithiocarbamate (INADTC). The effect of these chelating agents on the urinary excretion of manganese was more complex and was found to be dependent upon the level of loading of manganese as well as the individual chelating agent. For animals with drinking water containing 400 mg/liter of manganese, the administration of the chelating agents led to a decrease in the sum of the biliary plus urinary manganese excretion. The results are of special interest in that they show that under some conditions the administration of chelating agents can lead to changes other than those expected.