Smooth muscle cell (SMC) maturation during embryonic development of coronary arteries and veins was studied in rats using different markers of the contractile phenotypes. The spatio-temporal pattern of distribution of these markers compared with the developing tunica media was examined. Alpha-smooth muscle actin (alpha-SMA) was the first marker of the SMC in the tunica media of coronary arteries found in ED16 hearts, followed by smooth muscle myosin heavy chain isoform which occurred on ED17. Subsequently 1E12 antigen was expressed in coronary artery wall in ED18 hearts, and finally smoothelin. The markers occur within the proximal part of the coronary arteries and deploy toward the apex. They are also found within the great vessels. None of the markers except for the alpha-SMA were found in coronary veins during embryonic life. We conclude that the SMC population of the developing tunica media of coronary vessels differentiates by the acquisition of particular markers and this process lasts till the end of the prenatal and early postnatal life.

中文翻译：

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大鼠冠状动脉胚胎发育过程中平滑肌细胞表型的分化。

使用不同的收缩表型标记在大鼠中研究了冠状动脉和静脉的胚胎发育过程中的平滑肌细胞（SMC）成熟。与发育中的中膜介质相比，检查了这些标志物的时空分布。α-平滑肌肌动蛋白（alpha-SMA）是ED16心脏中冠状动脉的中膜中SMC的第一个标记，其次是ED17中出现的平滑肌肌球蛋白重链亚型。随后在ED18心脏的冠状动脉壁中表达1E12抗原，最后在平滑肌素中表达。标记出现在冠状动脉的近端部分内，并朝着顶点展开。它们也在大型船只中发现。在胚胎生命过程中，除冠状动脉外，均未发现除α-SMA外的其他标记。