engleski

Oral cadmium exposure and placental steroidogenesis in rats

We evaluated effects of oral cadmium exposure during gestation on distribution of essential trace element in maternal and foetal tissues and on placental steroids in rats. Female Wistar rats with regular 4-day estrous cycles were randomly assigned to Cadmium group (exposed to 50 ppm Cd as chloride in demineralised drinking water, 5.83±0.625 mg Cd/kg b.wt. a day, from gestation day 1) and to Control (supplied with demineralised drinking water ad libitum). Experiment ended on gestation day 20, mother rats were anaesthetised, exsanguinated from abdominal aorta after blood sampling from the hart, and liver, kidney, placentas and foetuses dissected, weighed and prepared for element analysis (by atomic absorption spectrometry). Placentas were also used for steroid hormone assay (by immuno-enzymatic methods). In Cadmium group, maternal body weights decreased, and organ, blood and foetal cadmium concentrations increased. Of essential trace elements, iron decreased in the maternal kidney, zinc decreased in placentas, and iron and zinc decreased in whole foetuses. Copper concentrations did not change. In Cadmium group, placental concentrations of progesterone increased and testosterone decreased. The results showed that cadmium accumulation in the placenta was associated with reduced transplacental transfer of iron and zinc from the mother rat to the foetuses and with placental steroid hormone disruption. All these could have unfavourable effects on foetal growth and development in utero and on postnatal organ and sexual development.

cadmium; essential trace elements; placenta; rat; steroid disruption

The presentation received IUTOX Junior Fellowship.