NCIt definition : A metal chelating agent that is used as an antidote in arsenic, gold, lead, mercury
and other heavy metal poisoning. Metals form ligands in the body with the sulfhydryl
groups of the pyruvate-oxidase enzyme system. This leads to an inhibition of the normal
functioning of these enzymes that are dependent on free sulfhydryl groups for their
activity. Dimercaprol reverses the enzyme inhibition by chelating the metal and regenerates
free sulfhydryl groups, thereby preventing and reversing the metals toxic effects.;