Attempts for contruction of arterial wall with medial smooth muscle cells in vitro -An approach foam developmental biology-

用抗α-平滑肌肌动蛋白的单抗，用免疫组织化学方法观察小鼠胚胎血管系统中平滑肌分化的初始阶段。9日龄胚胎血管系统中可见少量的平滑肌细胞，仅有背主动脉和脐动脉表现出明显的平滑肌分化；10日龄胚胎的背主动脉、脐动脉、脐肠系膜动脉、第3、4弓和颈内动脉均可清晰地识别出平滑肌细胞；11日龄胚胎的背主动脉、第6弓、体间动脉等血管均可见平滑肌细胞形成2~3层。从第9天的小鼠胚胎中分离出主动脉区域，将未分化的间充质细胞在含10%FBS的培养液中培养，3天后约80%的细胞出现α-平滑肌肌动蛋白免疫染色。被称为关键物质候选者的各种生长因子现在在胚胎诱导过程中进行了检查。

Initial phase of smooth muscle differentiation in the mouse embryonic vascular system was observed immunohistochemically by using monoclonal antibody against alpha-smooth muscle actin. Little smooth muscle cells were detected in the vascular system of 9 day embryo, where only dorsal aorta and umbilical artery showed simptone of smooth muscle differentiation.In 10 day embryo, smooth muscle cells clearly recognized in the dorsal aorta, umbilical artery, omphalomesenteric artery, 3rd and 4th aortic arches and internal carotid artery.In 11 day embryo, smooth muscle cells formed 2-3 layrs at dorsal aorta, in 6th aortic arches, intersomitic arteries and other vessels.We tried to construct a novel in vitro culture system in order to elucidate induction process of smooth muscle differentiation. Aortic regions were dissected from 9 day mouse embryos and undifferentiated mesenchymal cells were cultured in medium with 10%FBS.After 3 days alpha-smooth muscle actin immunostaining developed in about 80% of cells. various growth factors, known as candidates for key substances were now examined in embryonic induction processes.