模拟失重后家兔股静脉壁超微结构的变化(英文)

Ultrastructural changes of the wall of femoral vein after simulated weightlessness in rabbits

背景:目前对模拟失重的研究大多数只局限于对动脉系统的影响,对静脉系统的影响有待研究。目的:观察模拟失重对家兔股静脉壁超微结构及血管重塑的影响。设计:以实验动物为研究对像完全随机对照研究。单位:解放军第四军医大学航空航天医学系。材料:实验于2000-12/2001-12在解放军第四军医大学航空航天医学系完成。24只雄性健康新西兰兔,体质量2.0～2.5kg。干预:建立头低位(-20°)倾斜的模拟失重家兔模型。24只雄性健康新西兰兔,随机分为:对照组、模拟失重10d组、模拟失重21d组,每组8只。用透射电镜观察兔股静脉壁的超微结构。主要观察指标:电镜下观察静脉血管壁内皮细胞、线粒体、内弹力板、平滑肌层的变化及变性情况。结果:实验组家兔股静脉内皮细胞细胞器减少,线粒体溶解、消失;空泡变性增多并可见吞噬体;内弹力板变薄且有断裂;平滑肌层变薄,部分平滑肌细胞有变性,间质增多。模拟失重21d组较模拟失重10d组变化更明显。结论:在模拟失重影响下,家兔股静脉壁结构发生血管重塑性变化,呈萎缩性改变,模拟失重时间越长,改变越明显。

BACKGROUND:At present,most researches on simulated weightlessness are confine d to its effect on the artery.Therefore,the effect on the vein needs to be furth er studied. OBJECTIVE:To probe into the effect of simulated weightlessness on the ultrast ructure of rabbit femoral vein and the remodeling of femoral vein. DESIGN: A completely randomized and controlled trial based on experimental an imals. SETTING:Department of Aerospace and Aviation Medical Science,Fourth Military Medical University of Chinese PLA. MATERIALS: The experiment was completed in the Department of Aerospace and A viation Medical Science,Fourth Military Medical University of Chinese PLA from D ecember 2000 to December 2001.Altogether 24 healthy male New Zealand rabbits, we ighing 2.0- 2.5 kg were obtained. INTERVENTIONS:The model of Head- Down Tilt(- 20° )(HDT) simulated weightle ssness was established in rabbits.A total of 24 healthy male New Zealand rabbits were randomly divided into control group,10- day simulated weightlessness grou p and 21- day simulated weightlessness group, with 8 rabbits in each group.The ultrastructure of the rabbit femoral vein was observed under transmission electr on microscope. MAIN OUTCOME MEASURES:Changes and degeneration of endothelial cell,mitochondr ion,internal elastic membrane,and smooth muscle. RESULTS:Cell organelles in endothelial cell of the femoral vein of HDT rabbit s decreased,mitochondrion dissolved and disappeared,vacuolar degeneration in end othelial cell increased and phagolysosome in endothelial cell could be found.Int ernal elastic membrane became thinner and was broken.The smooth muscle layer bec ame thinner and some smooth muscle cells became degenerated.Cell interstitial su bstance increased.There was significant difference in changes between 21- day a nd 10- day simulated weightlessness groups. CONCLUSION:The vascular remodeling of femoral vein occurs with atrophic chang es during simulated weightlessness.The longer duration of simulated weightlessne ss is, the more obviously the structure of femoral vein changes.