微重力环境下立位耐力不良的发生机制(英文)  

Mechanism of orthostatic intolerance in microgravity

作　　者：岳勇[1] 姚永杰[2] 赵东风[1] 吴兴裕 

机构地区：[1]解放军第二一医院骨科,辽宁省大连市116021 [2]解放军第四军医大学航空航天医学系,陕西省西安市710032

出　　处：《中国临床康复》2003年第27期3694-3696,F003,共4页Chinese Journal of Clinical Rehabilitation

基　　金：国家自然科学基金(30000197)~~

摘　　要：目的:观察模拟失重对兔股静脉压力-容积关系的影响及静脉壁显微结构的变化,探讨微重力环境下造成立位耐力不良的发生机制。方法:采用头低位(-20°)倾斜的方法作为模拟失重家兔模型。24只雄性健康新西兰兔,随机分为对照组、模拟失重21d组和模拟失重10d组,每组8只。进行股静脉的压力-容积关系测试,并观察血管壁的显微结构。结果:模拟失重后股静脉P-V曲线向容积变化比增大的方向移动(同对照组比较P<0.01),模拟失重21d组较10d组移动更明显(P<0.01)。加载、卸载时,模拟失重21d组的P-V二次抛物线方程式系数B1,B2的值犤加载时为(3.6±1.6)10-2,(3.3±2.8)×10-4;卸载时(4.2±1.8)10-2,(4.6±3.4)×10-4〗显著高于对照组犤加载时为(1.3±0.6)10-2,(0.4±0.3)×10-4;卸载时(1.8±1.0)10-2,(0.8±0.8)×10-4犦及模拟失重10d组犤加载时为(1.7±0.6)10-2,(0.8±0.6)×10-4;卸载时(2.1±0.6)10-2,(1.3±0.7)×10-4〗(P<0.01),模拟失重10d组的B1,B2的值和对照组相比有增加的趋势。组织学研究表明,模拟失重组股静脉内皮细胞呈立方或矮柱状并有细胞脱落,平滑肌层变薄等变化。结论:模拟失重后股静脉顺应性增加,同时股静脉管壁结构也发生明显改变。AIM:To observe the changes of pressure-volume(P-V) relationship of the femor al veins of rabbits after exposure to simulated weightlessness and to explore th e mechanism of orthostatic intolerance in microgravity. METHODS:Sixteen healthy male New Zealand rabbits were subjected to head-down tilt(HDT) at -20O to simulate the condition of weightlessness, and were randoml y divided into 21 d HDT group,10 d HDT group and control group(8 in each),with a nother 8 serving as normal control group.The P-V relationships of the femoral v eins were investigated after the exposure. RESULTS:The femoral vein P-V relationship curves of HDT groups tended to shif t to greater volume change ratio than that of control group(P< 0.01), and the sh ift was more obvious in 21d HDT group(P< 0.01).B1 and B2 in the quadratic equati ons of 21d HDT group[Inflow: B1=(3.6±1.6)×10-2,B2=( 3.3±2.8)×10-4;outflow: B1=(4.2±1.8)×10-2,B2=( 4.6±3.4)×10-4]were significantly higher than the va lue of 10 d HDT group[Inflow:B1=(1.7±0.6)×10-2,B2=(0.8±0.6)×10-4;outflow:B 1=(2.1±0.6)×10-2,B2=( 1.3±0.7)×10-4]and control group[Inflow:B1=(1.3±0.6) ×10-2,B2=( 0.4±0.3)×10-4;outflow:B1=(1.8±1.0)×10-2,B2=( 0.8±0.8)×10-4 ] during inflow and outflow(P< 0.01).

关 键 词：微重力环境 立位耐力不良 模拟失重 股静脉 压力-容积关系 动物实验 

分 类 号：R852.22[医药卫生—航空、航天与航海医学]