Lactational Transfer of Cadmium in Rodents – CNS Effects in the Offspring

This thesis comprises studies on the transfer of cadmium (Cd) from the lactating dam to the suckling and CNS effects of Cd during development, using rodents as a model. The purpose has been to conduct low–level exposure studies relevant for risk assessment of Cd. Cadmium is recognised as a toxic environmental contaminant with renal dysfunction considered as the critical effect after long-term exposure. For the non-smoking, non-occupationally exposed population, food, especially of vegetable origin, is the main source of cadmium exposure. Cd concentration in suckling pup kidney was strongly correlated with Cd in milk and kidney of the Cd exposed lactating rats, showing that cadmium is transferred to the pup via milk and absorbed in the suckling. This indicates that Cd in kidney can be used as a biomarker of the Cd dose in pups. A prominent uptake and retention of Cd was demonstrated in the mammary tissue, where Cd binding to metallothionein was indicated. Cd in milk was present mainly in the fat and casein fractions with a smaller part in the whey fraction. The serotonergic system in the developing brain was found to be susceptible to Cd