Fitzharris T P, Thompson R P, Markwald R R
Tex Rep Biol Med. 1979;39:287-304.
The cells which will form the smooth muscle tunica media are derived embryologically from the cardiac mesenchyme referred to as endocardial cushion tissue. These progenitor smooth muscle cells, however, are derived primarily from aortic arch mesenchyme as opposed to the endocardium in the prevalvular areas. The matrical microenvironments of these cells begin to change at approximately 5 days of development when the progenitor smooth muscle cells acquire a more fibrillar matrix. The prospective adventitia and valvular areas still maintain an environment rich in hyaluronate and proteoglycans. By Day 6, the 110Ao microfibril, characteristic of smooth muscle cells, appears in the matrix well in advance of the amorphous elastin component seen at Days 8 and 9. The orientation of the collagenous microfibrils and elastic microfibrils is non-random with respect to the layers of cells, and this precludes a simple substrate alignment model in establishing the characteristic laminarity of this tissue.
形成平滑肌中膜的细胞在胚胎学上源自被称为心内膜垫组织的心脏间充质。然而，这些祖代平滑肌细胞主要源自主动脉弓间充质，而非瓣膜前区域的心内膜。当祖代平滑肌细胞获得更多纤维状基质时，这些细胞的基质微环境在发育约5天时开始发生变化。预期的外膜和瓣膜区域仍维持富含透明质酸和蛋白聚糖的环境。到第6天，平滑肌细胞特有的110Ao微原纤维在基质中出现，早于第8天和第9天所见的无定形弹性蛋白成分。胶原微原纤维和弹性微原纤维的取向相对于细胞层是非随机的，这排除了在建立该组织特征性分层时的简单底物排列模型。
