Effect Of Maternal Exposure To Trace Cadmium On Gonadal Differentiation And Development In Male Offspring Rats

Objective: To investigate the effect and mechanism of maternalexposure to trace cadmium on the differentiation and development in fetaltestis.Methods:16pregnant female SD rats were randomly divided into4groups with4in each group: CdCl2treated group (group A) wasintraperitoneally injected with CdCl2(1.5mg/kg.d) on9th,11th,13th day ofthe gestation period respectively; DES group(group B) was subcutaneouslyinjected with DES (100μg/kg.d) from day9to17of gestation period; CdCl2+TMX group(group C) was treated with CdCl2(same as above)+TMX(50mg/kg.d); normal control group (group D) was treated with normal salineinstead of CdCl2with same dose. On day18of gestation period, the pregnantrats were killed, the fetuses were removed, the body weight and sex ratio was recorded. While, fetus testis were used for histological and ultrastructuralobservation, immunohistochemistry of StAR and the expression of MIS withRT-PCR.Results:（1） Compare with group D, there were no significantalternation in the number and sex ratio of fetuses, but the body weight wassignificantly decreased in group A and group B.（2） By the HE-staining, Sertoli cells arranged in disorder inseminiferous tubules as well as interstitial hyperplasia were observed ingroup A and group B, whereas histological changes in group C were noobvious compared with group D.（3）Ultrastructural changes including swollen mitochondria andexpanded endoplasmic reticulum in Sertoli cells, gonocyte and Leydig cells,moreover, lipid droplets cumulated in Leydig cells were observed in group Aand group B, and so changes in group C were slightly more than those ingroup A or group B.（4）The positive expression of StAR in Leydig cells was significantlydecreased in group A and group B (P<0.05), but, there was no difference inthe expression of StAR between group C and group D (P＞0.05).（5）there was no difference in the levels of MIS expression betweengroups (P＞0.05). Conclusion:(1) cadmium is a definite environmental endocrinedisruptor which has the similar effect as estrogen would affect gonadaldifferentiation and development in male fetal rats.(2) The effect of maternal exposure to trace cadmium on thedifferentiation and development in fetal testis is not through the MISapproach. Objective: To investigate the effect and mechanism of maternalexposure to trace cadmium on the differentiation and development inoff-spring testes.Methods:16pregnant female SD rats were randomly divided into4groups with4in each group: CdCl2treated group (group A) wasintraperitoneally injected with CdCl2(1.5mg/kg.d) on9th,11th,13th day ofthe gestation period and every other day during lactation respectively; DES group(group B) was subcutaneously injected with DES (100μg/kg.d) fromday9th to17th of gestation period and every other day during lactationrespectively; CdCl2+TMX group(group C) was treated with CdCl2(same asabove)+TMX (50mg/kg.d); control group (group D) was treated with normalsaline instead of CdCl2with same dose. On day30th after parturition, theweight and sex ratio of off-spring male rats were recorded; While, off-springtestis were used for ultrastructural observation, Immunofluorescence of StARand the expression of inhibin-B with RT-PCR.Results:(1) Compare with group D,there were no significant alternationin the number and sex ratio of off-spring rats among each group onPND30,the body weight was significantly decreased in group A and group B.(2) Ultrastructural changes including swollen mitochondria andexpanded endoplasmic reticulum in Sertoli cells, gonocyte and Leydig cells,moreover, lipid droplets cumulated in Leydig cells were observed in group Aand group B, and so changes in group C were slightly more than those ingroup A or group B.(3) The positive expression of StAR in Leydig cells was significantlydecreased in group A and group B (P<0.05), but there was no difference inthe expression of StAR between group C and group D (P＞0.05).(4) The levels of inhibin-B expression was significantly decreased ingroup A and group B(P＜0.05)，however，there was no difference in theexpression of inhibin-B between group C and group D(P＞0.05). Conclusion:(1) Trace cadmium exposure during gestation and lactationcould cause the disorder of testicular differentiation and development onoff-spring male rats.（2）cadmium which has the similar effect as estrogen would decreaseexpression of StAR and inhibin-B in off-spring male rats.