锌对兔血管形态学影响的实验研究

Experimental study on effect of zinc on morphology of blood vessels

目的 观察高锌对兔血管病理形态的影响。方法 在新西兰雄性大白兔饮水中加葡萄糖酸锌（锌浓度 15.0 mmol/L）喂养12个月,动态观察血清及组织锌、铜变化,6及12个月时应用光镜、扫描电镜、透射电镜观察血管微细结构及超微结构变化。结果 兔在加锌喂养后血清及组织锌持续升高;随时间延长,主动脉血管增厚,弹性降低;光镜显示6个月时动脉血管内皮细胞肿胀、平滑肌细胞排列紊乱,12个月时平滑肌层增厚;电镜观察内皮细胞条索状排列变平、中断或消失,细胞连接疏松、凹陷,表面覆盖片状或（和）团块状沉积物。细胞核膜凹陷、固缩,核异、常染色质分布异常,胞浆膜破裂,线粒体空泡变,弹力纤维疏松,基底膜变形。结论 高锌可致兔血管壁脂质沉积及内皮细胞损伤,这可能是形成动脉粥样硬化的重要基础。

Objective To observe the effects of high zinc on the morphology of blood vessels in rabbits. Methods New Zealand white rabbits were fed with zinc gluconate (15.0 mmol/L zinc) in drinking water for 12 months. Zinc (Zn) and copper (Cu) in serum and tissues were measured. The changes of fine structure and ul-trastructure in aortae were observed by means of light microscope (LM),scanning electron microscope (SEM) and transmission electron microscope (TEM) on 6 and 12 months. Results The contents of Zn in serum and tissues were increased continuously after Zn supplementation. With the extension of time, aortas were thickened and elasticity of wall decreased, The observation of LM showed that endothelial cells (Ed) were swelled and the arrangement of smooth muscle cells (SMC) was disordered on 6 months . Thickness of vascular SMC was revealed on 12 months. SEM and TEM showed that striped bunchy arrangement of Ed became flat broken off and disappeared. Ed junction became loose and caved in the surface of Ed was covered with pieces and /or masses of precipitate. Subsidence of nuclear membrane, coagulation of nucleus, abnormal distribution of euchromatin and heterochromatin, split of plasmalemma, vascular degeneration of mitochondria, slackness of elastic fiber and metamorphosis of basement membrane were observed. Conclusions High Zn could cause lipid deposition of blood vessels and injury of endothelial cells in rabbits, which might be a major foundation for atherogenesis.