EFFECTS OF MESO-2,3-DIMERCAPTOSUCCINIC ACID OR 2,3-DIMERCAPTOPROPANE 1-SULFONATE ON BERYLLIUM-INDUCED BIOCHEMICAL-ALTERATIONS AND METAL CONCENTRATION IN MALE-RATS

The effects of two chelating agents, meso-2,3-dimercaptosuccinic acid (DMSA) and 2,3-dimercaptopropane 1-sulfonate (DMPS) on the mobilizatio n, distribution, hepatic and hematopoietic toxicity of beryllium were compared in male rats exposed to beryllium. Animals were exposed to be ryllium nitrate (0.5 mg/kg, orally, daily 5 days/week) for 21 days. Tw enty-four hours after the last dose they were injected with a chelatin g agent (DMSA or DMPS) (25 or 50 mg/kg, twice daily for 5 days). The a dministration of DMSA and DMPS at a dose of 50 mg/kg marginally elevat ed the fecal excretion of beryllium. DMPS was effective in depleting b eryllium from the liver, spleen and kidneys. However, DMPS (50 mg/kg) results in the redistribution of beryllium to blood. Beryllium-induced inhibition of hepatic alkaline phosphatase and hepatic adenosine trip hosphatase (ATPase) were restored considerably with the chelating agen ts. Also, hepatic and renal histopathological lesions were less marked in rats treated with DMPS (50 mg/kg) compared with those treated with beryllium per se and DMSA. These effects were more prominent at the 5 0-mg/kg dose of chelating agents than at 25 mg/kg. These results sugge st that treatment with DMPS has some beneficial effects in experimenta l beryllium intoxication.