孕期微量染镉对雄性胎鼠性腺分化发育影响的研究

目的：探讨孕期微量染镉对胎鼠睾丸分化发育的影响及作用机制。方法：SD孕鼠16只，随机分为镉组（A组）、己烯雌酚组（B组）、镉加他莫静酚组（C组）和正常对照组（D组），每组4只。A组于孕期第9、11、13天腹腔注射氯化镉1．5H影（kg．d），B组于妊娠第9至17天皮下注射已烯雌酚10％g／（kg．d），C组注射氯化镉的同时给予雌激素受体拮抗剂他莫昔酚50mg／（kg．d），D组注射与镉等体积生理盐水。妊娠第18天，削商产取雄性胎鼠睾丸作光、电镜观察；免疫组化测定各组胎鼠睾丸间质细胞类固醇激素合成急性调节蛋白（StAR）表达水平；RT—PCR法测定曲勒氏管抑制物（MIS）表达量。结果：光镜下A组和B组睾丸生精小管内支持细胞排列紊乱，间质成分增生，C组未见明显的形态学改变；电镜下A组和B组均可见支持细胞、生殖母细胞及间质细胞线粒体肿胀、内质网扩张以及间质细胞内脂滴堆积，C组超微结构退变轻于A组和B组；A组和B组间质细胞中StAR阳性产物表达均显著低于D组（P〈0．01），C组StAR阳性产物表达虽低于D组，其差异没有统计学意义（P〉0．05），但却明明显高于A组（P〈0．05）；各组间MIS表达差异无统计学意义（P〉0．05）。结论：孕期微量镉暴露可影响雄性胎鼠性腺的分化与发育，且镉具有雌激素样作用．

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

Objective： To investigate the effect and mechanism of matexnal exposure to trace cadmittm on the differentiation and development in fetal testes. Methods ： 16 matmt tern＇ale SD rats were randomly divided into 4 groups with 4 in each group： CdC]2 treated group （ group A ） was intraperitoneally injected with CDCI2 （ 1.5mg/kg. d） on 9th, 1 hh, 13th day of the gestation period respectively; DES group{ group B） was subcutaneously injected with DES （100p.g/kg. d } froro day 9 to 17 of gestation peried; CDCI2 ＋ TMX grouplgroup C） was treated with CDCI2 {same as above） ＋ TMX 50mg/kg.d） ; control group group D） was treated with nornval saline instead of CDCI2 with same dose. On day 18 of gestation period, caesarean section was conducted to get fetus~ then the testes were collected for histological and uhrastmetural observation, inmaunohistechemistry of STAR. Meanwhile, the levels of MIS expression were also determined by RT - PCR methed. Results： By the HE - staining, Sertoli cells arranged in disorder in seminifemas tubules as well as interstitial hyperplasia were observed in group A and group B, whereas histological changes in ~roup C were no obvious compared with group D. Uhrastructural changes including swollen mitochondria and expanded cndoplasmic reticulum in Sertali calls, genocyte and Leydig cells, moreover, lipid droplets cumulated in Leydig cells were. observed in group A and group B, and so changes in bT~up C were slightly more than those in group A or group B. The pt~ifive expression of StAR in Leydig cells was significantly decreased in groap A and group B （ P 〈 0.01 ）, but, there was no difference in the expression of StAR belween group C and group D （ P 〉 0.05 ）. In addition, there was no difference in the levds of MIS expression between groups （P 〉 0.05）. Conclusion： Maternal exposure to trace cmlmium during pregnant period would affect gonadal differentiation and development in male fetal rats; cadmium has the similar effect as estrogen.