Hogers B, DeRuiter M C, Baasten A M, Gittenberger-de Groot A C, Poelmann R E
Department of Anatomy and Embryology, University of Leiden, The Netherlands.
Circ Res. 1995 May;76(5):871-7. doi: 10.1161/01.res.76.5.871.
Intracardiac flow patterns during heart development were studied by injection of india ink into the yolk sac circulation of chick embryos at Hamburger-Hamilton stages 10 to 17. We injected india ink into a small venule or capillary, carefully preventing application of overpressure to the vascular system, and recorded the intracardiac route by video. From stage 12 onward, blood flow was laminar, and separate intracardiac currents were visualized. The yolk sac was divided into a left and a right half. Blood coursed through each half in concentric loops, ranging from the marginal sinus to the sinus venosus. This parallel array persisted within the heart. Bilateral to the embryo, two lateral regions arose that extended wedge-like within each half, resulting in six equally sized yolk sac regions at stage 16. The process of heart looping was not accompanied by a change in flow pattern. However, developmental changes of the yolk sac circulation were reflected in alteration of the intracardiac flow pattern. From stage 16 onward, the intracardiac flow pattern was no longer determined by the left- or right-hand side of the yolk sac but by bilateral anterior, lateral, and posterior regions of the yolk sac. Blood from the lateral regions of the yolk sac was preferentially distributed to the head. The results show that in preseptation stages a relatively stable flow pattern is present. We suggest that alterations in blood flow could influence the process of normal heart development.
通过向处于汉密尔顿-汉堡分期10至17期的鸡胚卵黄囊循环中注入印度墨水，研究了心脏发育过程中的心内血流模式。我们将印度墨水注入一条小静脉或毛细血管，小心避免对血管系统施加过压，并通过视频记录心内路径。从第12期开始，血流呈层流状态，并且可以观察到独立的心内血流。卵黄囊被分为左右两半。血液在每一半中以同心环流动，从边缘窦流向静脉窦。这种平行排列在心脏内持续存在。在胚胎两侧，出现了两个外侧区域，它们在每一半内呈楔形延伸，在第16期形成了六个大小相等的卵黄囊区域。心脏环化过程并未伴随血流模式的改变。然而，卵黄囊循环的发育变化反映在心内血流模式的改变上。从第16期开始，心内血流模式不再由卵黄囊的左侧或右侧决定，而是由卵黄囊的双侧前部、外侧和后部区域决定。来自卵黄囊外侧区域的血液优先分布到头部。结果表明，在分隔前期阶段存在相对稳定的血流模式。我们认为血流的改变可能会影响正常心脏发育过程。
