Effect of maternal exposure to trace cadmium on gonadal differentiation and development in male fetal rats

Objective: To investigate the effect and mechanism of maternal exposure to trace cadmium on the differentiation and development in fetal testes.Methods: 16 matured female SD rats were randomly divided into 4 groups with 4 in each group: CdCl2 treated group(group A) was intraperitoneally injected with CDCl2(1.5mg/kg.d) on 9th,l lth,13th day of the gestation period respectively;DES group(group B) was subcutaneously injected with DES(100μg/kg.d) from day 9 to 17 of gestation period;CDC12 +TMX group(group C) was treated with CDCl2(same as above)+TMX(50mg/kg.d);control group(group D) was treated with normal saline instead of CDCl2 with same dose.On day 18 of gestation period,caesarean section was conducted to get fetus,then the testes were collected for histological and ultrastructural observation,immunohistochemistry of STAR.Meanwhile,the levels of MIS expression were also determined by RT-PCR method.Results: By the HE-staining,Sertoli cells arranged in disorder in seminiferous tubules as well as interstitial hyperplasia were observed in group A and group B,whereas histological changes in group C were no obvious compared with group D.Ultrastructural changes including swollen mitochondria and expanded endoplasmic reticulum in Sertoli cells,gonocyte and Leydig cells,moreover,lipid droplets cumulated in Leydig cells were observed in group A and group B,and so changes in group C were slightly more than those in group A or group B.The positive expression of StAR in Leydig cells was significantly decreased in group A and group B(P 0.01),but,there was no difference in the expression of StAR between group C and group D(P0.05).In addition,there was no difference in the levels of MIS expression between groups(P0.05).Conclusion: Maternal exposure to trace cadmium during pregnant period would affect gonadal differentiation and development in male fetal rats;cadmium has the similar effect as estrogen.