Tomanek R J
Department of Anatomy and Cardiovascular Center, University of Iowa, Iowa City 52242, USA.
Cardiovasc Res. 1996 Feb;31 Spec No:E46-51.
Myocardial vascularization is initiated after endothelial cell precursors from the region of the liver or septum transversarium migrate to the newly formed epicardium. Blood island-like structures appear and form vascular channels along the epicardium and into the myocardium. Prior to this time myocardial cells receive nutrition directly from the ventricular lumen, a process which is facilitated by the highly trabecular arrangement of the ventricles. A venous system is formed prior to any evidence of arteries or arterioles. The formation of a vascular plexus in the region of the outflow tract is followed by penetration of these microvessels into the wall of the aorta. These ingrowing vessels merge, acquire a muscular coat and form the left and then the right coronary vessels. These events occur during a short period of time, e.g., 2 weeks in humans, 4 days in rats. Maturation of the arterial tree occurs primarily after birth. Our knowledge of the regulation of coronary vascularization during development is very limited. Accordingly, future studies need to focus on the role of growth factors, chemotactic factors, extracellular matrix molecules, and mechanical events.
心肌血管化始于来自肝脏区域或横隔的内皮细胞前体迁移至新形成的心外膜。血岛样结构出现，并沿心外膜形成血管通道并深入心肌。在此之前，心肌细胞直接从心室腔获得营养，心室高度小梁化的结构促进了这一过程。在出现任何动脉或小动脉迹象之前，静脉系统就已形成。流出道区域形成血管丛后，这些微血管穿透主动脉壁。这些向内生长的血管融合，获得肌层并形成左冠状动脉，然后是右冠状动脉。这些事件在短时间内发生，例如在人类中为2周，在大鼠中为4天。动脉树的成熟主要发生在出生后。我们对发育过程中冠状动脉血管化调节的了解非常有限。因此，未来的研究需要关注生长因子、趋化因子、细胞外基质分子和机械事件的作用。
