ORGAN CADMIUM DEPOSITS IN ORALLY EXPOSED FEMALE RATS AND THEIR PUPS AND THE DEPLETING EFFICIENCY OF SODIUM N-(4-METHOXYBENZYL)-D-GLUCAMINE-N-CARBODITHIOATE MONOHYDRATE (MEOBDCG)

Cadmium was given to female rats in the drinking water (50 ppm Cd) from 4 weeks before mating until weaning (a total of 10 weeks). Four weeks after the discontinuation of exposure, mothers and offspring were then given two i.p. doses of 1 mmol kg-1 sodium N-(4-methoxybenzyl)-D-glucamine-N-carbodithioate monohydrate (MeOBDCG) on subsequent days. Cadmium in kidneys and liver was determined in groups of mothers before mating and in mothers and pups after parturition, at the end of lactation and 4 and 5 weeks after the discontinuation of exposure. An additional measurement was made in pups in the middle of the lactation period. Cadmium deposition rapidly increased in the two organs between the 11th and 21st day of lactation. At all times, Cd concentrations in the liver and kidneys of mothers were several orders higher than in the offspring. After the discontinuation of exposure, maternal hepatic and renal Cd contents showed a significant decrease. Treatment with the chelator depleted the hepatic Cd stores in mothers by 90% and in pups by 80%, while the corresponding renal depletions were only 23% and 12%, respectively. The liver and kidney contents of Cd (but not the concentration) increased by a higher factor during lactation than during pregnancy and exposure during lactation was also more important for pups than prenatal exposure. The lower efficiency of the chelator in the offspring indicates that Cd accumulated during the neonatal period was less accessible to treatment with chelating agents than Cd accumulated in later life. It is more likely that with increasing Cd concentration a smaller proportion of Cd is bound to strong binding sites.