Experimental Studies of Endothelial Regeneration in the Rabbit Carotid Arteries after Endarterectomy-Spindle and Ovoid Type Cells of the Normal Diet Group versus the Hypercholesterolemia Group-

本实验观察了兔颈动脉内膜剥脱术后内皮细胞再生的情况，包括去除内皮细胞、内弹力层和部分肌层。术后每隔1小时至8周观察再生情况。实验分为两组，A组为日本大白兔，饲喂标准饲料；B组为兔，手术前喂1%胆固醇饲料1个月，术后持续至处死动物。A组术后3d动脉内膜表面扫描电镜下可见梭形和卵圆形细胞，形态与管壁表面的梭形细胞不同。术后2周内皮细胞重新生长。内皮再生完成后，卵圆形细胞定位于低切应力区域。透射电子显微镜显示卵圆形细胞由胞质小泡组成，结构紧密相连。免疫组织化学结果显示卵球形细胞染色的因子阳性，这证实了他们的内皮来源。B组内皮细胞再生速度与A组无明显差异，但扫描电镜下可见梭形细胞增大，卵圆形细胞不规则。透射电子显微镜显示梭形细胞和卵圆形细胞内均有空泡。免疫组织化学显示B组卵圆形细胞CD31阳性，证实其来源为内皮细胞。此外，RAM11染色的泡沫细胞向内皮下迁移，之后可见内膜增厚。

Endothelial regeneration of the rabbit carotid artery was investigated after endarterectomy, which involved the removal of a 4mm length including the endothelium, internal elastic laminae and part of the muscle layr of the media. Regeneration was studied at intervals from 1 hour to 8 weeks after surgery. There were two groups, Group A consisting of Japan White rabbits fed a standard diet and Group B consisting of rabbits fed a 1% cholesterol diet for a month before the surgery and continued after surgery until the annimals were killed. In Group A,scanning electron microscopy (SEM) showed spindle type and ovoid type cells which were morphologically different from spindle type cells on the Juminal surface of the endarteretomized wall on day 3 after sugery. Endothelial regrowth 2 weeks after the sugery was confirmed. After the endothelial regrowth was completed, the ovoid type cells were localized in the low shear stress area. Transmission electron microscopy (TEM) showed the ovoid type cell consisted of pinocytic vesicles and in structure were tightly joined. Immunohistochemical findings showed the ovoid type cell stained positivery for factor, which confirmed their endothelial origin. In Group B the speed of the endothelial regrowth was not remarkably different from that in Group A,but SEM revealed enlarged spindle type cells and irregular-sized ovoid type cells. TEM showed vacuoles existed in both spindle type and ovoid type cells. Immunohistochemically the Croup B ovoid type cells stained positively for CD31, which confirmed their endothelial origin. In addition, foam cells which were stained for RAM11 migrated subendothelially, after which intimal thickening was observed.