Ikeda T, Iwasaki K, Shimokawa I, Sakai H, Ito H, Matsuo T
Department of Pathology, Nagasaki University School of Medicine, Japan.
Anat Embryol (Berl). 1990;182(6):553-62. doi: 10.1007/BF00186462.
The distribution pattern of Leu-7 (HNK-1) in developing human embryonic hearts and rat hearts was studied by immunohistochemistry. Human and rat embryos at Streeter's stages XIII approximately XX and fetus stage I were used. Leu-7, which is absent in the newborn rat heart, is expressed transiently in the embryo and fetus I stages. The earliest embryonic heart shows two incomplete circular structures with immunoreactivity in the myocardium along the primitive atrioventricular cushion and bulboventricular canal. These two structures become localized topographically in the definitive atrioventricular node and atrioventricular bundle after rearrangement and partial disappearance during embryonic development. At Streeter's stages XVIII approximately XX, Leu-7 immunoreactivity appears to localize topographically in almost all the pathways of the conduction system, although some discontinuities are observed in the atrioventricular junction and atrial internodal tracts. Thereafter, immunoreactivity decreases gradually and differentially by site and stage. The precise nature of Leu-7 immunoreactive cells, that is, whether or not they are neurogenic or myogenic, is not revealed by this study. The present observations are discussed in connection with the hypothesis that specialized ring tissue is the primordium of the conduction system.
通过免疫组织化学方法研究了Leu - 7（HNK - 1）在人类胚胎心脏和大鼠心脏发育过程中的分布模式。使用了处于Streeter分期XIII至XX期左右的人类和大鼠胚胎以及胎儿I期。Leu - 7在新生大鼠心脏中不存在，在胚胎期和胎儿I期短暂表达。最早的胚胎心脏显示出两个不完整的圆形结构，沿着原始房室垫和球室管的心肌有免疫反应性。在胚胎发育过程中经过重新排列和部分消失后，这两个结构在解剖学上定位到了最终的房室结和房室束。在Streeter分期XVIII至XX期左右，Leu - 7免疫反应性似乎在传导系统的几乎所有路径上按解剖学定位，尽管在房室交界和心房结间束中观察到一些不连续性。此后，免疫反应性按部位和阶段逐渐不同程度地降低。本研究未揭示Leu - 7免疫反应性细胞的确切性质，即它们是否为神经源性或肌源性。结合特殊环组织是传导系统原基的假说对目前的观察结果进行了讨论。
