Glycogen content of placenta and of fetal and maternal liver in cadmium-exposed rats. I: A descriptive light microscopic study.

Female Wistar rats were injected subcutaneously with CdCl2 (0.49 mg Cd/kg/day) daily during pregnancy. Placentae, fetal livers and maternal livers were prepared for histological investigation of the glycogen content 14, 16, 18, 19 and 20 days after mating. The glycogen content was estimated semiquantitatively in periodic acid-Schiff-(PAS-)stained sections. The development of the glycogen content of the placenta and the fetal liver from days 14 to 20 of pregnancy in control animals is described and compared with the development of the glycogen content of these tissues from cadmium-exposed animals. No clear changes due to cadmium exposure were observed in the glycogen content of maternal and fetal livers, nor in the spongiotrophoblast and the islets of glycogen in the placenta. The glycogen content in the placental labyrinth increased from day 14 up to day 18 in both control and cadmium-exposed animals. In control animals, the glycogen content decreased after day 18, whereas it remained high in the placental labyrinth of cadmium-exposed animals; this might be considered as a feature of retarded maturation. Regulating mechanisms and similarities between the effects of cadmium exposure and the diabetic state are discussed.