Effects of oral cadmium exposure during pregnancy on maternal and foetal element distribution and steroidogenesis in rats

In recent years cadmium has been recognized of having potency to act as metalloestrogen in mammals. We investigated earlier effects of parenteral exposure to cadmium (total dose 5 mg Cd/kg s.c.) in pregnant rats and found that it caused perturbations in element concentrations in maternal and foetal compartments, serum oestradiol concentration, and placental progesterone production (BioMetals 17:1-14, 2004 ; In: TEMA 10, Pt.V/1:809-12, 2000). We initiated new investigation aimed at assessing effects of cadmium exposure on steroidogenesis and element distribution in mother rats and foetuses. Female rats (Wistar) are exposed to 50 ppm Cd (as CdCl2xH2O) in demineralised water (Cd-exposed) or demineralised water (Control) from gestation day (GD)1-GD19. Calculated daily dose based on drink intake is 6.4+/-0.3 mg Cd/kg b.wt. On GD19 mother rats are killed (by exsanguination from heart and abdominal aorta in parenteral anaesthesia). Preliminary results showed increased cadmium concentrations in all analysed tissues of Cd-exposed rats except whole foetuses. Zinc concentrations were decreased in placental tissue and whole foetus. Oral cadmium exposure during pregnancy disrupts foetal zinc concentrations, an essential element for protein synthesis and organ development. Steroid disruption is yet to be evaluated.