Sadler T W, Cardell R R
Anat Rec. 1977 May;188(1):103-23. doi: 10.1002/ar.1091880110.
Developing neuroepithelial cells from the cranial region of neural folds were examined at various intervals from 15 minutes to four hours after administration of teratogenic (250 mg/kg) or embryolethal (500 mg/kg) doses of HU to ICR/DUB mice on ninth day of gestation. Thirty percent of surviving fetuses showed extencephaly after the teratogenic dose. The initial ultrastructural change in some neuroepithelial cells occurred within 15 minutes to one hour after treatment with the teratogenic dose and involved a breakdown of polyribosomes into monosomes which were dispersed evenly in the cytosome. At one to two hours, condensation of the cytoplasm and chromatin was observed along with distorted nuclear shape. At two to four hours, cells exhibited extremely condensed cytoplasm and fragmentation of the cells occurred. The affected cells showed pyknotic nuclei and segregation of fibrillar and granular components of the nucleolus. In some nuclei, particularly after treatment with the higher dose of HU, a condensation of the nucleolus was observed. At this stage images were obtained which indicated that neighboring cells phagocytosed the cellular fragments derived from the HU affected cells.
在妊娠第9天给ICR/DUB小鼠施用致畸剂量（250mg/kg）或胚胎致死剂量（500mg/kg）的HU后，在15分钟至4小时的不同时间间隔检查神经褶颅区发育中的神经上皮细胞。致畸剂量后，30%存活胎儿出现脑膨出。在用致畸剂量处理后15分钟至1小时内，一些神经上皮细胞出现初始超微结构变化，涉及多核糖体分解为单核糖体，单核糖体均匀分散在细胞质中。1至2小时时，观察到细胞质和染色质凝聚，同时核形状扭曲。2至4小时时，细胞表现出极度凝聚的细胞质，细胞发生破碎。受影响的细胞显示核固缩以及核仁纤维状和颗粒状成分分离。在一些细胞核中，特别是在用较高剂量的HU处理后，观察到核仁凝聚。在此阶段获得的图像表明，相邻细胞吞噬了源自HU影响细胞的细胞碎片。
