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切除术后的内皮再生情况。内膜切除术包括切除4 mm长的中膜，包括内皮、内弹力层和部分肌层。术后1小时至8周的时间间隔进行再生研究。分为两组，A组为日本白色家兔，饲喂标准饲料; B组为家兔，在手术前一个月饲喂1%胆固醇饲料，并在手术后继续饲喂，直至动物被处死。A组术后第3天扫描电镜下见梭形和卵圆形细胞，形态与梭形细胞不同。术后2周证实内皮再生。内皮再生完成后，卵圆形细胞位于低切应力区。透射电镜（TEM）显示卵圆形细胞由胞饮小泡组成，结构紧密。免疫组化结果显示卵圆形细胞因子染色阳性，证实其来源于内皮细胞。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，卵圆形细胞不规则。透射电镜显示梭形和卵圆形细胞内均存在空泡。免疫组织化学显示B组卵圆形细胞对CD 31染色阳性，证实其为内皮细胞来源。此外，RAM 11染色的泡沫细胞向内皮下迁移，之后观察到内膜增厚。

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.