Captopril and glutathione inhibit the superoxide dismutase activity of Hg (II).

The purpose of this study was to determine if captopril, an angiotensin-converting enzyme inhibitor, and glutathione could interact with mercuric ions and so modify the catalytic dismutation of superoxide carried out by this metal. With an assay that generates superoxide anion radicals without the intervention of metal ions increasing concentrations of both reagents progressively inhibited the breakdown of superoxide brought about by mercury. Maximum inhibition was attained with a molar ratio of captopril (glutathione): Hg (II) = 1. These results may help to explain the protective and/or antioxidative effect of thiol compounds during mercury intoxication.