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

用抗α-平滑肌肌动蛋白单克隆抗体，对小鼠胚胎血管系统平滑肌分化的初期进行了免疫组化观察。9天胚胎的血管系统中几乎没有平滑肌细胞，仅在背主动脉和脐动脉处有平滑肌分化，10天胚胎的背主动脉、脐动脉、脐肠系膜动脉、第3、4主动脉弓和颈内动脉处有平滑肌细胞，11天胚胎的背主动脉处有2-3层平滑肌细胞，本研究试图建立一种新的体外培养体系，以阐明平滑肌细胞的诱导分化过程。从9天的小鼠胚胎中分离出主动脉区，将未分化的间充质细胞培养在含10%FBS的培养基中，3天后约80%的细胞出现α-平滑肌肌动蛋白免疫染色。现在在胚胎诱导过程中对各种生长因子进行了检查，这些生长因子被称为关键物质的候选物。

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.