孕鼠胎盘膜对混合稀土常乐的屏障作用  

Barrier Effect of Placenta Membrane of Pregnancy Rat on Mixed Rare Earth "Changle

作　　者：周莉[1] 陈辉[1] 黄可欣[1] 李树蕾[1] 聂毓秀[1] 

机构地区：[1]吉林大学基础医学院组织胚胎学教研室,吉林长春130021

出　　处：《中国稀土学报》2004年第2期295-298,共4页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金资助项目(29890280-3)

摘　　要：为评估混合稀土常乐对人体胚胎的潜在危害,在光镜和电镜下观察了混合稀土常乐染毒后的胎盘组织,以了解其在胎盘组织中的存在形式和分布情况,同时应用电感耦合等离子体质谱法(ICP MS)检测染毒后的孕鼠血清、胚胎组织提取液和羊水中的稀土含量以确定其能否通过胎盘屏障。染毒于雌鼠妊娠第六天开始,每天分别以0.3,2,5和20mg·kg-1混合稀土常乐灌胃,直至妊娠第十八天。结果显示:光镜下,染毒组胎盘绒毛中毛细血管周围合体细胞滋养层胞质内积聚有许多圆形黑色细小颗粒,颗粒的多少与染毒剂量呈正相关;电镜下,染毒组胎盘绒毛中可见有膜包裹的致密体及合体细胞滋养层细胞内线粒体有不同程度的空泡变和嵴断裂;ICP MS检测:孕鼠血清铈的含量随染毒剂量的增加而递增,染毒组胎儿羊水和孕鼠血清中稀土总量,只有20mg·kg-1组与对照组相比有显著增加,其余各组均无显著差异。胚胎组织提取液中各组的稀土总含量没有变化。由此得出结论:胎盘膜对混合稀土常乐进入胚体有很大的限制作用,但是,当混合稀土常乐在胎盘膜中积累增加到一定程度时,可少量透过胎盘屏障,进入胚体。To assess the potential health risks of mixed rare earths 'Changle' for human embryo, it should determine that whether Changle can cross placenta membrane, or placenta barrier initially. So the placenta tissue contaminated by Changle was observed under optical light and electron microscope to find out the distribution and existance of mixed rare earth Changle in placenta tissue. Meanwhile the content of rare earths in serum of pregnant rat, amniotic fluid and extract of embryo tissue were measured by using inductively coupled plasma-mass spectrometer (ICP-MS). The rats were administered with 0.3, 2, 5 and 20 mg·kg^(-1) mixed rare earths Changle every day orally from the 6th to 18th day after pregnancy. The results show that many particles are found in syncytialtrophoblast around capillaries of placental villi in contaminated groups under optical microscope, and there are more particles following increased dose. It was also observed that some dense bodies with the envelope in placenta membrane and the mitochondria crista within syncytialtrophoblast cytoplasm are damaged to different extent in contaminated groups under transmission electron microscope (TEM). Results of ICP-MS assay indicate that the level of Ce increases with increasing contamination dose in the serum of pregnant rats, the level of total rare earth elements remarkably roses in amniotic fluid and serum of pregnant rats for 20 mg·kg^(-1) group as compared with the control and no change for the other groups. In conclusion, the placenta barrier has significant effect on mixed rare earth Changle, but it still may enter fetus body when it accumulates enough to cross placenta barrier.

关 键 词：孕鼠 胎盘膜 混合稀土常乐 存在形式 分布 饲料添加剂 安全性 

分 类 号：S816.72[农业科学—饲料科学]