Abundant, durable, malleable, resistant to corrosion: No wonder lead has been such a popular metal throughout human history. Ancient Romans found a multitude of uses for it, from lining water pipes and drinking vessels to sweetening wine. What they didn't realize were the detrimental health effects of this metal. It is now believed that lead poisoning was responsible for the bizarre behavior, mental incompetence, gout, stillbirths, and sterility that afflicted the Roman aristocracy- and quite possibly contributed to the decline of the Roman Empire.
Fast forward to 1921, when General Motors engineer Thomas Midgley, Jr., came up with another use for lead. As a gasoline additive, it reduced engine knock and improved performance. Of course, it was known to be toxic. Thomas Midgley himself was plagued with a "mysterious illness" while experimenting with it and, in 1924, 15 refinery workers died and 300 more became severely psychotic as a result of working with leaded gasoline.
Division of Pharmacology and Toxicology, Defence Research and Development Establishment, Jhansi Road, Gwalior 474 002, India; E-Mail: vidhudrde@gmail.com
Swaran J.S. Flora* * Author to whom correspondence should be addressed; E-Mail: sjsflora@drde.drdo.in; sjsflora@hotmail.com; Tel.: +91-751-234-4301; Fax: +91-751-234-1148.
Abstract Chelation therapy is the preferred medical treatment for reducing the toxic effects of metals. Chelating agents are capable of binding to toxic metal ions to form complex structures which are easily excreted from the body removing them from intracellular or extracellular spaces. 2,3-Dimercaprol has long been the mainstay of chelation therapy for lead or arsenic poisoning, however its serious side effects have led researchers to develop less toxic analogues. Hydrophilic chelators like meso-2,3-dimercaptosuccinic acid effectively promote renal metal excretion, but their ability to access intracellular metals is weak. Newer strategies to address these drawbacks like combination therapy (use of structurally different chelating agents) or co-administration of antioxidants have been reported recently. In this review we provide an update of the existing chelating agents and the various strategies available for the treatment of heavy metals and metalloid intoxications. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2922724/
