Influence of methionine administration during chelation of cadmium by CaNa(3)DTPA and DMPS in the rat.

Influence of methionine administration was investigated in rats on the efficacy of calcium trisodium diethylenetriamine pentaacetate (CaNa(3)DTPA) and 2,3-dimercaptopropane-1 sulfonate (DMPS) in the treatment of cadmium intoxication. CaNa(3)DTPA, DMPS or methionine were quite effective in mobilizing cadmium from blood and all the tissues examined in cadmium pre-exposed animals. The combination of CaNa(3)DTPA and methionine was more efficient in reducing hepatic, renal and heart cadmium levels while that of DMPS and methionine was more efficient in lowering liver, kidney and brain cadmium levels than either of them alone. The combinations were also highly effective in enhancing the urinary and the fecal excretion of cadmium. The treatment with CaNa(3)DTPA, DMPS or methionine was quite effective in reversing cadmium inhibited tissue enzymes and alterations in blood and serum biochemical levels. The combined treatment with a chelator and methionine was more effective than the chelators alone in restoring cadmium induced changes in hepatic and renal transaminases. The treatment with CaNa(3)DTPA, DMPS or methionine appreciably decreased the depletion of endogenous zinc, copper and iron due to cadmium but the combined treatments were more efficient than the individuals in restoring the kidney and the brain copper levels only. The results show that the administration of methionine during chelation therapy may be beneficial in the treatment of cadmium intoxication.