静脉内皮细胞功能和组织形态与高脂血症的关系(英文)

Correlating endothelial cell functions andhistomorphology to hyperlippemia

背景：自体静脉移植是临床治疗冠状动脉粥样硬化性心脏病的常用手段，明确其在移植前的基础病变，将为进一步研究移植静脉的保护，降低移植静脉的再狭窄奠定基础。目的：观察冠状动脉粥样硬化性心脏病的独立影响因素高脂血症对可用于移植静脉内皮功能和组织形态的影响。设计、时间及地点：随机对照动物实验，于2005-04/10在解放军第二军医大学附属长海医院全军心脏外科重点实验室完成。材料：选用成年雄性健康家兔50只，按随机数字表法分为对照组和高脂血症模型组，每组25只。方法：对照组予以普通饮食，每只每日喂饲基础饲料100～120g，饮水不限。高脂血症模型组予以高脂饮食，即除普通饮食外，每只每日加喂胆固醇1g。主要观察指标：分别在实验前和喂养2，4，8，12周末，采集血样本，获取颈内静脉标本，检测血脂水平；观察颈内静脉内皮型一氧化氮合酶蛋白表达、一氧化氮生成量和组织形态变化。获取静脉标本前应用超声多普勒检测颈内静脉和颈动脉血流，并观察其管壁厚度、管腔内径以及有无脂质或粥样硬化斑块等。结果：①高脂血症模型组家兔高脂喂养8周末血脂水平高于实验前及对照组（P〈0．01），并稳定于此较高水平，同时出现颈动脉脂质斑块。②高脂血症模型组家兔高脂喂养8，12周末颈内静脉内皮型一氧化氮合酶蛋白表达水平、一氧化氮生成量低于实验前及对照组（P〈0．05），可见内皮剥脱，弹力纤维明显减少甚至消失，未见泡沫细胞和粥样斑块。结论：高脂血症可导致静脉内皮功能不全和组织形态学异常，但若将其作为桥血管材料移植到动脉系统，将会严重影响移植静脉的重塑，甚至导致移植静脉再狭窄。

BACKGROUND： Autologous vein transplantation is a common means for clinical treatment of coronary atherosclerotic heart disease. Identification of basic pathological changes of autologous vein transplantation will provide basis for further studies on how to protect transplanted vein and reduce the possibility of restenosis of transplanted vein. OBJECTIVE： This study was designed to investigate effects of hyperlipemia, an independent influential factor, on venous endothelial functions and histomorphology. DESIGN, TIME AND SETTING： This study, a randomized controlled animal experiment, was performed at the key laboratory of Department of Cardiothoracic Surgery, Changhai Hospital, Second Military Medical University of Chinese PLA. MATERIALS： A total of 50 healthy adult male rabbits were randomly and equally divided into a control group and a hyperlipemia group. METHODS： In the control group, rats were dally fed with normal diet 100-120 g. In the hyperlipemia group, rats were daily fed with normal diet 100-120 g plus cholesterol lg. For all rats, water was freely available. MAIN OUTCOME MEASURES： Prior to and 2,4,8, and 12 weeks after feeding, blood sample and cervical vein specimens were taken for detection of blood lipid levels and observation of endothelial nitricoxide synthase （eNOS） expression, nitric oxide （NO） production, and histomorphologic change. Prior to harvesting vein sample, blood flow of jugular vein and carotid artery was examined using ultrasonic Doppler flowmeter. Simultaneously, histopathological changes including the thickness of intima and media, the diameter of the veins, and the presence of lipid or atherosclerotic plaque were observed. RESULTS： Eight weeks after feeding, blood lipid levels in the hyperlipemia group were significantly higher than those prior to feeding and in the control group （P 〈 0.01）, and maintained at this level. Obvious lipid plaques formed in the carotid artery of rabbits in the hyperlipemia group. Eight and twelve weeks after feeding, eNOS expression levels and NO production in the jugular veins were lower than those prior to feeding and in the control group （P 〈 0.05）. Simultaneously, endothelial denudation was noticed and the elastic fibers almost disappeared in the hyperlipemia group; there were no foam cells or lipid plaques. CONCLUSION： Hyperlipemia may result in endothelium dysfunction and histomorphological change of venous conduit. Nevertheless, autogenous vein transplanted into artery system, will greatly influence the remodeling of transplanted vein, even lead to restenosis of transplanted vein.