Guyton J R, Karnovsky M J
Am J Pathol. 1979 Mar;94(3):585-602.
The relationship of intimal smooth muscle cell proliferation in the permanently occluded rat carotid artery to the presence or absence of luminal platelets was examined. Blood was rinsed from the arterial lumen immediately after occlusion and was replaced by autologous, citrated platelet-rich plasma (PRP, 6 to 20 X 10(5) platelets/microliter) or filtered platelet-poor plasma (PPP, less than 100 platelets/microliter). Occluded arteries were studied after 1 to 28 days by light and electron microscopy. Events occurring within the first 2 days included fibrin clot formation, endothelial degeneration and denudation, transmural migration of polymorphonucelar leukocytes and monocytes, and, in PRP-filled arteries, degranulation and disappearance of platelets. By 7 days a neointima was formed by macrophages and undifferentiated cells. The latter cells had some features of vascular smooth muscle cells and were apparently derived from medial cells which traversed the internal elastic lamina. After 14 days, identifiable smooth muscle cells emerged as the predominant cell type in a rapidly growing intimal plaque. No differences could be discerned between arteries originally filled with PRP or PPP. This experimental model is similar to atherosclerosis in dimensions of avascular area and in coexistence of degenerative, inflammatory, and proliferative processes. Cell proliferation deep within an atherosclerotic plaque could be initiated by factors other than platelets, perhaps by products of inflammatory cells.
研究了永久性闭塞大鼠颈动脉内膜平滑肌细胞增殖与管腔内血小板存在与否的关系。闭塞后立即从动脉腔冲洗出血液，并用自体枸橼酸化富血小板血浆（PRP，6至20×10⁵个血小板/微升）或过滤后的贫血小板血浆（PPP，少于100个血小板/微升）替代。在1至28天后，通过光镜和电镜对闭塞动脉进行研究。最初2天内发生的事件包括纤维蛋白凝块形成、内皮变性和剥脱、多形核白细胞和单核细胞的透壁迁移，以及在充满PRP的动脉中血小板脱颗粒和消失。到7天时，巨噬细胞和未分化细胞形成了新内膜。后者细胞具有一些血管平滑肌细胞的特征，显然源自穿过内弹力层的中膜细胞。14天后，可识别的平滑肌细胞成为快速生长的内膜斑块中的主要细胞类型。最初充满PRP或PPP的动脉之间没有差异。这个实验模型在无血管区域的大小以及退行性、炎症性和增殖性过程的共存方面与动脉粥样硬化相似。动脉粥样硬化斑块深处的细胞增殖可能由血小板以外的因素引发，也许是由炎症细胞的产物引发。
