Filip D A, Radu A, Simionescu M
Circ Res. 1986 Sep;59(3):310-20. doi: 10.1161/01.res.59.3.310.
Interstitial cells of heart atrioventricular and sigmoid valves were examined in several laboratory animals (rabbit, hamster, rat, and mouse) and in humans. These cells constitute a large fraction of the total cell population of the valve; in mouse atrioventricular valves, they amount to approximately 30% of the volumetric density. By their ultrastructural features and functional properties, valvular interstitial cells are intermediate between fibroblasts and vascular smooth muscle cells. Like fibroblasts, valvular interstitial cells lack a basal lamina establishing direct and extensive contacts with collagen fibers, elastin microfibrils, and proteoglycans of the matrix. The cells have numerous slender and long processes, connected to one another, forming a complex cellular framework spanning the entire valve. Similar to smooth muscle cells, valvular interstitial cells are extensively coupled by communicating junctions as shown by thin sections, freeze-fracture, lanthanum staining, and carboxyfluorescein microinjection. The cells contain numerous bundles of actin filaments, which are decorated by the S1 fragment of heavy meromyosin. Valvular interstitial cells also express cyclic guanosine-monophosphate-dependent protein kinase, as detected by immunofluorescence and immunoperoxidase histochemistry. Motor nerve endings are located closely apposed to valvular interstitial cells: structurally most of them appear to be of the adrenergic type. Valvular interstitial cells contract on epinephrine or angiotensin II stimulation as shown both in culture and in situ (valvular strips). Taken together these observations suggest that VIC may have contractile properties, which can account for a controlled tonus, actively correlated with the cyclically changing forces acting on valves during diastole and systole.
在几种实验动物（兔、仓鼠、大鼠和小鼠）以及人类中，对心脏房室瓣和乙状结肠瓣膜的间质细胞进行了检查。这些细胞占瓣膜总细胞群的很大一部分；在小鼠房室瓣中，它们约占体积密度的30%。根据其超微结构特征和功能特性，瓣膜间质细胞介于成纤维细胞和血管平滑肌细胞之间。与成纤维细胞一样，瓣膜间质细胞缺乏基膜，与基质中的胶原纤维、弹性蛋白微原纤维和蛋白聚糖建立直接而广泛的联系。这些细胞有许多细长且相互连接的突起，形成一个跨越整个瓣膜的复杂细胞框架。与平滑肌细胞相似，如薄切片、冷冻断裂、镧染色和羧基荧光素显微注射所示，瓣膜间质细胞通过通讯连接广泛耦合。细胞含有许多肌动蛋白丝束，这些丝束被重酶解肌球蛋白的S1片段标记。通过免疫荧光和免疫过氧化物酶组织化学检测发现，瓣膜间质细胞还表达环磷酸鸟苷依赖性蛋白激酶。运动神经末梢紧邻瓣膜间质细胞定位：在结构上，它们中的大多数似乎是肾上腺素能型的。如在培养物和原位（瓣膜条）中所示，瓣膜间质细胞在肾上腺素或血管紧张素II刺激下会收缩。综合这些观察结果表明，瓣膜间质细胞可能具有收缩特性，这可以解释一种受控的张力，这种张力与舒张期和收缩期作用于瓣膜的周期性变化力密切相关。
