维生素D诱发大鼠动脉粥样硬化的实验研究

EXPERIMENTAL ATHEROSCLEROSIS IN RATS INDUCED BY VITAMIN D

将雄性Ｗｉｓｔａｒ大鼠２４只随机分成１个对照组和３个实验组。实验组一次性腹腔注射维生素Ｄ（ＶＤ）６０万单位／ｋｇ体重，对照组同时注射等容量生理盐水。实验组分别在３，１８和３４ｄ不同时程以及对照组在３４ｄ各取主动脉作石蜡切片（ＨＥ染色）和超薄切片，在光镜及透射电镜下观察，结果发现：光镜下，实验组３ｄ组血管壁未见明显变化；１８ｄ主动脉壁平滑肌增生，内皮及内皮下层有水肿变性；３４ｄ平滑肌增生明显，肌细胞排列紊乱，弹性纤维层结构不清，粥样斑块向管腔内突出。电镜下，实验组３ｄ则可见内皮细胞有短突凸向管腔，胞质内有大小不等的空泡；１８ｄ内皮突起多而高，呈微绒毛状，内弹性膜断裂，胶原纤维增多；３４ｄ内皮细胞核扭曲，内皮下胶原纤维增生，可见泡沫细胞，内弹性膜断裂处有平滑肌细胞伸入。对照组光镜和电镜结构均与正常无异。本研究提供了一种简易、经济、快捷地诱发动脉粥样硬化模型的方法。

Twenty four male Wistar rats were divided into 4 equal groups at random,with 3 groups for experiments and 1 for control.Atherosclerotic lesions of the aorta were induced in experimental groups by intraperitoneal injection of vitamin D with a single dose of 600 000 international units per kilogram body weight.The 3 experimental groups were sacrificed at intervals of 3,18 and 34 days respectively and the control group at 34 days,Specimens from thoracic and abdominal aorta were taken for observation. The results showed:Under light microscope there were slight proliferation of smooth muscle cells and edematous degeneration of endothelial cells and subendothelial tissue at the end of the 18th day.The elastic laminae ruptured and smooth muscle cells proliferated. Projected atherosclerotic plaques were seen on the luminal surface of the aortic wall between 18 and 34 days,Under electron microscope,projections of endothelial cells were observed on the luminal surface and there were vesicles of various sizes in the cytoplasm by the end of the 3rd day up to 18 days,projections of the endothelial cells were numerous and microvillous;After 18 days,nuclei of the endothelial cells became twisted and smooth muscle cells migrated from tunica media to intima through the ruptured elastica interna. Some smooth muscle cells had become foam cells,The structure of the control group remained intact.This study offers a simple,economic and quick method for induction of atherosclerosis in experimental animals.