Effect of Cadmium on Trophoblast Cell Proliferation and Apoptosis in Different Gestation Periods of Rat Placenta.

In this study, we aimed to show how cadmium (Cd) affects the trophoblast proliferation and differentiation in the placenta and the apoptotic activity in different gestational days and, hence, its effects of placental development with immunohistochemical and TUNEL techniques. Experimental model of our study consisted of placental development of control and Cd groups on 15, 17, 19, and 21th days of the gestation. Female rats in Cd groups were subcutaneously administered a single dose of 0.5 mg Cd/kg/day dissolved in sodium chloride as 2 mL/kg Cd chloride until the day they sacrificed. Embryo and placenta of female rats were separately removed on 15, 17, 19, and 21th days of the gestation in which the placental development takes place and placentas were processed for microscopic examinations. In the placentas of the control group, all layers were observed to be formed on the 15th gestational day and thereafter a continuous growth was monitored. In the Cd group also all layers existed from the 15th gestational day. However, they were smaller in size than control groups. Frequency of proliferating cell nuclear antigen (PCNA)-positive cells was decreased and the number of apoptotic cells was increased in all the gestational days related to Cd. In conclusion, Cd administered during the pregnancy was observed to cause abnormal placental development by disrupting the normal structure of the placenta, inhibiting the proliferation of trophoblast and increasing the number of apoptotic trophoblast cells.