Aoyama N, Kikawada R, Yamashina S
Department of Internal Medicine, Kitasato University School of Medicine, Sagamihara, Japan.
Arch Histol Cytol. 1993 Aug;56(3):303-15. doi: 10.1679/aohc.56.303.
Morphological aspects of the heart conduction system have been studied by various histochemical markers. However, the actual presence of markers in the conduction system and its developmental mode remain controversial. We have shown the anti-Leu-7 antibody to cross-react with cells of the rat embryonic heart conduction system by an immuno-electron microscopic study. A comparison was thus made between the results of Leu-7 immunohistochemistry and those by other markers previously used for studying the development of the conduction system. As a result, Leu-7 immunoreactivity proved the most reliable marker for studying the conduction system of the developing rat heart. Examination of the developmental mode of a rat conduction system was facilitated with the use of this marker. The immunoreactivity for Leu-7 initially appeared in the anterior wall of the bulboventricular region at 10 days of development. The development of three internodal tracts and two atrioventricular nodes was demonstrated in the following stage. These primordial atrioventricular nodes, one of which connects to a bundle of His, fused to form a single distinctive node followed by completion of the conduction system in the 18 day fetus.
心脏传导系统的形态学方面已通过各种组织化学标记物进行了研究。然而，传导系统中标记物的实际存在情况及其发育模式仍存在争议。我们通过免疫电子显微镜研究表明，抗Leu-7抗体与大鼠胚胎心脏传导系统的细胞发生交叉反应。因此，对Leu-7免疫组织化学的结果与先前用于研究传导系统发育的其他标记物的结果进行了比较。结果表明，Leu-7免疫反应性是研究发育中大鼠心脏传导系统最可靠的标记物。使用该标记物有助于对大鼠传导系统的发育模式进行研究。Leu-7的免疫反应性最初在发育10天时出现在球室区域的前壁。在接下来的阶段显示了三条结间束和两个房室结的发育。这些原始房室结中的一个与希氏束相连，融合形成一个独特的结，随后在18天的胎儿中完成传导系统的发育。
