The Effect of Penicillamine and 2,3-Dimercaptosuccinic Acid on Urinary Excretion and Tissue Distribution of Gold

Abstract

In order to study interactions in vivo between Au⁺ and SH-containing agents, groups of mice were given 35 μmol/kg of radiolabelled [¹⁹⁵Au] thiomalate (Myocrisin) intramuscularly. The administration of Myocrisin is known to result in protein-bound gold and free thiomalate (mercaptosuccinate). High doses of dimercaptosuccinate (1 mmol/kg daily) increased the urinary excretion of radiolabelled gold [¹⁹⁵Au] for several days. Treatment for 7 days with 1 mmol/kg of penicillamine or dimercaptosuccinate reduced the blood and kidney levels of gold to 30–50% of the controls. The oral administration of penicillamine in high doses, 1–10 mmol/kg, increased significantly the urinary excretion of [¹⁹⁵Au] the first day after the Myocrisin injection, but on the subsequent days the radio-metal excretion was unaffected by the treatment. A lower dose level of penicillamine (0.3 mmol/kg daily) gave rise to only a small and insignificant increase in the urinary excretion of gold. The present results indicate that penicillamine at low clinical doses is an inefficient chelator of gold, while high doses (presumably comparable to about 1200 mg daily in humans) may mobilize certain amounts of the metal deposits.