van der Lei B, Schakenraad J M
Department of General Surgery, University Hospital of Groningen, The Netherlands.
Cell Tissue Res. 1988;254(3):647-54. doi: 10.1007/BF00226515.
To study the effect of haemodynamic stress on the morphological differentiation of pseudointima, the ultrastructure of the cells lining normally shaped and aneurysmal polyurethane vascular prostheses implanted into the abdominal aorta of rats was examined. In the normally shaped vascular prostheses the pseudointima was composed of several layers of smooth muscle cells, which varied in differentiation from normal smooth muscle cells to myofibroblasts, and which were lined by a continuous sheet of endothelial cells. In the aneurysmal vascular prostheses, a pseudointima, composed of only layers of smooth muscle cells had developed. Those smooth muscle cells which lined the lumen had a typical morphology: they were polygonal, flat cells of unequal size, with a distinct organelle-free zone, containing myofilaments, at the luminal peripheral cytoplasmic side. The other smooth muscle cells varied in differentiation from normal smooth muscle cells to myofibroblasts. Under severe haemodynamic stresses, such as occur in the aneurysmal vascular prostheses, the regeneration of endothelial cells is impaired and smooth muscle cells undergo morphological changes to form a pseudoendothelial lining.
为研究血流动力学应激对假内膜形态分化的影响，对植入大鼠腹主动脉的正常形状和动脉瘤样聚氨酯血管移植物内衬细胞的超微结构进行了检查。在正常形状的血管移植物中，假内膜由几层平滑肌细胞组成，这些平滑肌细胞的分化程度从正常平滑肌细胞到肌成纤维细胞不等，并且内衬有连续的内皮细胞层。在动脉瘤样血管移植物中，仅由几层平滑肌细胞组成的假内膜已经形成。那些内衬管腔的平滑肌细胞具有典型的形态：它们是大小不等的多边形扁平细胞，在管腔周围细胞质侧有一个明显的无细胞器区，含有肌丝。其他平滑肌细胞的分化程度从正常平滑肌细胞到肌成纤维细胞不等。在严重的血流动力学应激下，如动脉瘤样血管移植物中发生的情况，内皮细胞的再生受损，平滑肌细胞发生形态变化以形成假内皮内衬。
