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应用全胚胎培养、体内致畸敏感期毒性试验二种方法并结合扫描电镜及光镜技术探讨和比较了砷、甲基汞对大鼠卵黄囊胎盘发育及造血功能的影响.结果发现:砷对卵黄囊胎盘的损害作用远大于甲基汞;光镜下卵黄囊胎盘直径和血管分化得分值逐渐下降,畸胎率随着给药浓度的增加而不断升高,呈剂量-反应关系;扫描电镜下砷组内皮层细胞表面微绒毛数量减少和变短,细胞膜上出现空洞样病变,重者膜崩解残缺不全,间皮层细胞表面微绒毛回缩或消失,细胞膜表面亦有明显的空洞和崩解等病理改变.卵黄囊胎盘-胚胎血循环障碍、微血管数量减少、血岛减少等病变揭示卵黄囊胎盘结构和功能改变与砷的致畸机制关系密切;而汞的致畸机制主要与其直接攻击胚胎细胞有关,但在高剂量时亦对卵黄囊胎盘血管分化有一定的抑制作用.
The effects of arsenic and methylmercury on the placental development and hematopoietic function of yolk sac in rats were investigated by using two methods of whole embryo culture and in vivo teratogenicity sensitive test combined with scanning electron microscopy and light microscopy.The results showed that arsenic The damage of yolk sac placenta was far greater than that of methylmercury. Under the light microscope, the yolk sac placental diameter and the score of vascular differentiation gradually decreased, and the rate of teratogenic rate increased with the increase of dose, which showed a dose-response relationship. Under the electron microscope, the number of microvilli on the surface of arsenic group decreased and shortened, and the cavity-like lesions appeared on the cell membrane, the disintegration and disintegration of the membrane were serious, the microvilli retracted or disappeared on the cell surface of the arsenic group, Disintegration and other pathological changes of the yolk sac placenta - embryonic blood circulation disorders, reduced the number of microvessels, reduced blood Island and other lesions revealed yolk sac placental structure and function changes and arsenic teratogenic mechanism is closely related to the teratogenic mechanism of mercury and its direct attack Embryonic cells, but also in high doses of yolk sac placental vascular differentiation have a certain inhibitory effect.