呼吸内胚层及第二生心区与小鼠胚胎心动脉端发育关系

Association of Pulmonary Endoderm and the Second Heart Field with Development of the Distant of Mouse Embryonic Heart

目的:探讨呼吸内胚层及第二生心区与小鼠胚胎心动脉端发育的关系。方法:对35例胚龄9~13 d小鼠胚胎心连续石蜡切片应用抗音猬因子(Shh)、抗Ptc1、抗Smo、抗心肌肌球蛋白重链(MHC)、抗胰岛因子(ISL-1)、抗α-平滑肌肌动蛋白(α-SMA)抗体进行免疫组织化学和免疫荧光化学染色。结果:胚龄9~11 d,呼吸内胚层开始发育,其腹侧形成Ptc1阳性的内胚层细胞索,与紧邻的第二生心区咽前ISL-1阳性间充质细胞形成对称的锥体形结构,顶端突入动脉囊腔。胚龄12~13 d,随内胚层细胞索消失,气管腹侧ISL-1阳性间充质细胞数量明显减少,心包内主动脉和肺动脉分离。结论:发育中的呼吸内胚层可能通过Shh信号通路为第二生心区咽前ISL-1阳性间充质细胞的发育聚集提供位置信息,参与小鼠胚胎心流出道的正常形态发生。

Objective：To explore the relationship of pulmonary endoderm and the second heart field with development of the distant of the mouse embryonic heart.Method：Serial sections of thirty-five mouse embryos from embryonic day（ED）9 to embryonic day（ED）13 were stained immunohistochemically or immunofluorescently with antibodies against Sonic Hedgehog（Shh）,Patched（Ptc1）,Smoothened（Smo）,myosin heavy chain（MHC）,islet 1（ISL-1）,α-smooth muscle actin（α-SMA）.Result：From ED9 to ED11,pulmonary endoderm started to develop,and formed a solid endoderm cord with Ptc1 positive expression which was surrounded by ISL-1 positive prepharyngeal mesenchyme in the second heart field projected into the aortic sac.During ED12 to ED13,following the disappearance of endoderm cord,the quantity of ISL-1 positive mesenchyme cells was obviously reduced,aorta and pulmonary artery were totally seprated.Conclusion：The developing pulmonary endoderm probably provides the positional information for the aggregation of ISL-1 positive prepharyngeal mesenchyme in the second heart field to take part in the morphogenesis of the outflow tract in mouse embryonic heart.