2.3- Dimercaptopropyl phthalamidic acid

Arsenic uptake in rabbit intestine is inhibited by phosphate, casein, and various metal-chelating agents (USEPA 1980). Mice and rabbits are significantly protected against sodium arsenite intoxication by (V-(2,3-dimercaptopropyl)phthalamidic acid (Stine et al. 1984). Conversely, the toxic effects of arsenite are potentiated by excess dithiols, cadmium, and lead, as evidenced by reduced food efficiency and disrupted blood chemistry in rodents (Pershagen and Vahter 1979). 

N-(2,3-Dimercaptopropyl)phthalamidic acid (41, DMPA) has been shown to form relatively stable complexes with cadmium, zinc and mercury312. DMPA has also been shown to enhance faecal and urinary excretion of mercury in mice and arsenic in mice and rabbits. For the decorporation of arsenic, taken in as arsine, the administration of 3-(tolylthio)propane-l, 2-dithiol (42) has been proposed in the USSR313. ... 

Lewisite. British anti-lewisite is also effective against other heavy metals, such as gold, excessive copper deposition seen in Wilson s disease (El-Youssef, 2003), and mercury (Goldman and Dacre, 1989). Newer analogs of BAL have been synthesized to improve efficacy, such as DMSA, 2,3-dimer-capto-1-propane sulfonic acid, and A-(2,3 dimercaptopropyl-phthalamidic acid) (DMPA). 

Treatment with dimercaptans was shown to increase the rate of As excretion in urine of rabbits after s.c. injection of lmgAs /kg (Maiorino and Aposhian 1985). Injection intramuscularly of 2,3-dimercapto-l-propanesulfonic acid (DMPS), me50-2,3-dimercaptosuccinic acid (DMSA), or /V-(2,3-dimercaptopropyl)-phthalamidic acid (DMPA) before As treatment increased the rate of urinary excretion of total As during the first 24 h after administration but did not affect the cumulative amount of As excreted between 0 and 48 h. A change in As species in urine (increased iAs and... 

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