Septation of the Intrapericardial Arterial Trunks in the Ear Human Embryonic Heart
Septation of the Intrapericardial Arterial Trunks in the Ear Human Embryonic Heart作者机构:Department of Histology and Embryology Shanxi Medical University Taiyuan Shanxi 030001 China
出 版 物:《Chinese Medical Journal》 (中华医学杂志(英文版))
年 卷 期:2018年第131卷第12期
页 面:1457-1464页
核心收录:
基 金:supported by a grant from the National Natural Science Foundation of China
主 题:Aortopulmonary Septum: Human Embryonic Heart Immunohistochemistry Outflow Tract: Outflow Tract Cushion
摘 要:Background: Outflow tract (OFT) septation defects are a common cause of congenital heart disease. Numerous studies have focused on the septation mechanism of the OFT, but have reported inconsistent conclusions. This study, therefore, aimed to investigate the septation of the aortic sac and the OFT in the early embryonic human heart. Methods: Serial sections of 27 human embryonic hearts from Carnegie stage (CS) 10 to CS19 were immunohistochemically stained with antibodies against α-smooth muscle actin (α-SMA) and myosin heavy chain. Results: At CS10-CS11, the OFT wail was an exclusively myocardial structure that was continuous with the aortic sac at the margin of the pericardial cavity. From CS13 onward, the OFT was divided into nonmyocardial and myocardial portions. The cushion formed gradually, and its distal border with the OFT myocardium was consistently maintained. The aortic sac between the fourth and sixth aortic arch arteries was degenerated. At CS16, the α-SMA-positive aortopulmonary septum formed and fused with the two OFT cushions, thus septating the nonmyocardial portion of the OFT into two arteries. At this stage, the cushions were not fused. At CS19, the bilateral cushions were fused to septate the myocardial portion of the OFT. Conclusions: Data suggest that the OFT cushion is formed before the aortopulmonary septum is formed. Thus, the OFT cushion is not derived from the aortopuhnonary septum. In addition, the nonmyocardial part of the OFT is septated into the aorta and pulmonary trunk by the aortopulmonary septum, while the main part of the cushion fuses and septates the myocardial portion of the OFT.