Thiomolybdates: mediators of molybdenum toxicity and enzyme inhibitors

The evidence for a role for thiomolybdates in the important ruminant disease syndromes of molybdenosis and Mo-induced hypocuprosis is outlined and present knowledge of their chemistry and metabolism in vivo is reviewed in an attempt to provide a less empirical basis for their toxicology. The compounds are novel enzyme inhibitors in vitro and have also been used therapeutically, apparently successfully, in the treatment of Wilson's disease. While the changes which occur in vivo are complex they can be best understood in terms of an alteration in the affinities for copper of some of the competing ligands, including albumin, which leads to a change in the distribution of copper between the different systemic pools and an overall depletion.