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-

研究了兔颈动脉内膜切除术后的内皮再生情况，切除了4mm长的内皮、内弹性板和部分中膜肌肉层。术后每隔1小时至8周研究再生情况。实验分为两组，A组为标准日粮饲喂的日本大白兔，B组为术前饲喂1%胆固醇日粮一个月，术后继续饲喂，直至处死。A组术后第3天，扫描电镜观察到动脉内膜壁小肠壁表面出现纺锤型和卵形细胞，与纺锤型细胞形态不同。手术后2周内皮细胞再生得到证实。内皮细胞再生完成后，卵形细胞定位于低剪应力区。透射电镜显示卵形细胞由胞泡组成，结构紧密相连。免疫组化结果显示卵形细胞因子染色阳性，证实其内皮来源。B组内皮细胞再生速度与A组无明显差异，但扫描电镜显示梭形细胞增大，卵形细胞大小不规则。透射电镜显示纺锤形细胞和卵形细胞均存在液泡。免疫组织化学染色显示B组卵形细胞CD31阳性，证实其来源于内皮细胞。此外，RAM11染色后的泡沫细胞在内皮下迁移，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.