Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida, USA.
Anat Rec (Hoboken). 2012 May;295(5):764-8. doi: 10.1002/ar.22432. Epub 2012 Feb 21.
In the prenatal heart, right-to-left atrial shunting of blood through the foramen ovale is essential for proper circulation. After birth, as the pulmonary circulation is established, the foramen ovale functionally closes as a result of changes in the relative pressure of the two atrial chambers, ensuring the separation of oxygen depleted venous blood in the right atrium from the oxygenated blood entering the left atrium. Little is known regarding the process of anatomical closure of the foramen ovale in the postnatal heart. Genetically engineered mouse models are powerful tools to study heart development and to reveal mechanisms underlying cardiac anomalies, including defects in atrioventricular septation. Using three-dimensional reconstructions of serial sectioned hearts at early postnatal Days 2-7, we show a progressive reduction in the size of the interatrial communication throughout this period and complete closure by postnatal Day 7. Furthermore we demonstrate that fusion of the septum primum and septum secundum occurs between 4 weeks and 3 months of age. This study provides a standard timeline for morphological closure of the right-left atrial communication and fusion between the atrial septa in normal mouse hearts.
在胎儿心脏中，血液通过卵圆孔从右心房向左心房的左右分流对于正常循环至关重要。出生后，随着肺循环的建立，卵圆孔由于两个心房腔之间的相对压力变化而在功能上关闭，从而确保将含氧的血液从右心房进入左心房与含氧的静脉血分开。关于出生后心脏中卵圆孔的解剖学闭合过程知之甚少。基因工程小鼠模型是研究心脏发育和揭示心脏异常机制的有力工具，包括房室间隔缺陷。我们使用出生后第 2-7 天的连续切片心脏的三维重建，显示在此期间房间隔沟通的大小逐渐减小，并在出生后第 7 天完全闭合。此外，我们证明了原发隔和继发隔之间的融合发生在 4 周到 3 个月的年龄之间。这项研究为正常小鼠心脏中左右心房沟通的形态闭合以及心房间隔之间的融合提供了一个标准的时间轴。
