Matsumoto E, Hirosawa K, Abe K, Naka S
Anat Embryol (Berl). 1984;169(3):249-59. doi: 10.1007/BF00315630.
Vitamin A-storing cells in perinatal mouse liver were studied by chemical and autoradiographic analyses of exogenous vitamin A. The amount of retinyl palmitate in the fetal liver increased significantly following oral administration of retinyl acetate to the mother, suggesting the existence of storage sites of the vitamin in fetal liver. Light microscope semi-serial autoradiography of the fetal liver on the 15th day of gestation showed that 3H-vitamin A administered to the mother was incorporated into cells distributed exclusively along the hepatic blood vessels and the blood islands. Mitotic figures of the labeled cells were frequently observed. Electron microscope autoradiography revealed that the vitamin was incorporated into lipid droplets, rough endoplasmic reticulum and Golgi apparatus of the fibroblast-like cells in close apposition to the endothelial cells. The labeled cells differed in their ultrastructure from the vitamin A-storing cells (Ito cells) of the adult liver. In the later gestational period, silver grains tended to be more concentrated in lipid droplets, and the cytological features of the labeled cells became similar to those of the vitamin A-storing cells. Both retinyl palmitate content and the labeling of lipid droplets increased rapidly in the liver of neonates after commencement of suckling. The labeled cells had the same appearance as the vitamin A-storing cells (Ito cells). It is concluded that vitamin A transported across the placenta is taken up in the fetal liver by the cells distributed along the blood vessels, and that these cells proliferate in accordance with vascular development and gradually take on the characteristics of vitamin A-storing cells during the perinatal period. A defensive role of the vitamin A-storing cell against the toxic effects of vitamin A is also suggested.
通过对外源性维生素A进行化学分析和放射自显影分析，对围产期小鼠肝脏中储存维生素A的细胞进行了研究。给母体口服醋酸视黄酯后，胎肝中棕榈酸视黄酯的含量显著增加，这表明胎肝中存在该维生素的储存部位。对妊娠第15天的胎肝进行光学显微镜半连续放射自显影显示，给母体注射的3H-维生素A被纳入仅沿肝血管和血岛分布的细胞中。经常观察到标记细胞的有丝分裂象。电子显微镜放射自显影显示，该维生素被纳入与内皮细胞紧密相邻的成纤维细胞样细胞的脂滴、粗面内质网和高尔基体中。标记细胞的超微结构与成年肝脏中储存维生素A的细胞（伊托细胞）不同。在妊娠后期，银颗粒倾向于更集中在脂滴中，标记细胞的细胞学特征变得与储存维生素A的细胞相似。哺乳开始后，新生儿肝脏中棕榈酸视黄酯含量和脂滴标记均迅速增加。标记细胞与储存维生素A的细胞（伊托细胞）外观相同。结论是，通过胎盘转运的维生素A在胎肝中被沿血管分布的细胞摄取，并且这些细胞随着血管发育而增殖，并在围产期逐渐具有储存维生素A的细胞的特征。还提示了储存维生素A的细胞对维生素A毒性作用的防御作用。
