Poelmann R E, Gittenberger-de Groot A C, Mentink M M, Bökenkamp R, Hogers B
Department of Anatomy and Embryology, University of Leiden, The Netherlands.
Circ Res. 1993 Sep;73(3):559-68. doi: 10.1161/01.res.73.3.559.
The endothelium of the coronary vascular system has been described in the literature as originating from different sources, varying from aortic endothelium for the main coronary stems, endocardium for the intramyocardial network, and sinus venosus lining for the venous part of the coronary system. Using an antibody against quail endothelial cells (alpha-MB1), we investigated the development of the coronary vascular system in the quail (Hamburger and Hamilton stages 15 to 35) and in a series of 36 quail-chicken chimeras. In the chimeras, pieces of quail epicardial primordium and/or liver tissue were transplanted into the pericardial cavity of a chicken host. The results showed that the coronary vascular endothelial distribution closely followed the formation of the epicardial covering of the heart. However, pure epicardial primordium transplants did not lead to endothelial cell formation, whereas a liver graft with or without an epicardial contribution did have this capacity. The first endothelial cells were seen to reach the heart at the sinus venosus region, subsequently spreading through the inner curvature to the atrioventricular sulcus and the outflow tract and, last of all, over the ventricular surfaces. At these sites, the precursor cells and small vessels were seen to invade the sinus venosus wall, the ventricular and atrial myocardium, and the mesenchymal border of the aortic orifice. Connections with the endocardium of the heart tube were only observed in the right ventricular outflow region. Initially, the connections with the aortic endothelium were multiple, but later in development only two of these connections persisted to form the proximal part of the two main coronary arteries. Connections to the pulmonary orifice were never observed. Our transplantation data showed that the entire coronary endothelial vasculature originated from an extracardiac source. Moreover, using the developing subepicardial layer as a matrix, we showed that the endothelial cells reached the heart from the liver region. Ingrowth into the various cardiac segments was also observed. Implications for the relation to specific congenital cardiac malformations are discussed.
冠状动脉系统的内皮在文献中被描述为起源于不同的来源，从主要冠状动脉主干的主动脉内皮、心肌内网络的心内膜，到冠状动脉系统静脉部分的静脉窦衬里各不相同。我们使用一种针对鹌鹑内皮细胞的抗体（α-MB1），研究了鹌鹑（汉堡和汉密尔顿第15至35阶段）以及一系列36个鹌鹑-鸡嵌合体中冠状动脉系统的发育情况。在嵌合体中，将鹌鹑心外膜原基和/或肝组织块移植到鸡宿主的心包腔内。结果表明，冠状动脉内皮分布紧密跟随心脏心外膜覆盖物的形成。然而，单纯的心外膜原基移植并未导致内皮细胞形成，而有或无心外膜贡献的肝移植则具有这种能力。最早可见内皮细胞到达心脏的静脉窦区域，随后通过内弯曲扩散到房室沟和流出道，最后遍布心室表面。在这些部位，可见前体细胞和小血管侵入静脉窦壁、心室和心房心肌以及主动脉口的间充质边界。仅在右心室流出区域观察到与心管心内膜的连接。最初，与主动脉内皮的连接有多个，但在发育后期，这些连接中只有两个持续存在，形成两条主要冠状动脉的近端部分。从未观察到与肺动脉口的连接。我们的移植数据表明，整个冠状动脉内皮血管系统起源于心外来源。此外，以发育中的心外膜下层为基质，我们表明内皮细胞从肝脏区域到达心脏。还观察到内皮细胞向内生长到各个心脏节段。文中讨论了其与特定先天性心脏畸形关系的意义。
