15d-6°头低位卧床对女性立位耐力的影响  

Effects of 15 d-6° Head-down Bed Rest on Female Orthostatic Tolerance

作　　者：谈诚[1] 曹毅[1] 张丽芬[1] 袁敏[1] 王惠娟[1] 牛东滨[1] 赵琦[1] 李志利[1] 陈文娟[1] 杨鸿慧[1] 王林杰[1] 李莹辉[1] 白延强[1] 

机构地区：[1]中国航天员科研训练中心,航天医学基础与应用国家重点实验室,北京100094

出　　处：《航天医学与医学工程》2011年第4期246-252,共7页Space Medicine & Medical Engineering

基　　金：国家重点基础研究计划(2011CB711000);中国航天医学工程预先研究项目(2008SY5406001)

摘　　要：目的研究15 d-6°头低位卧床(HDBR)对女性立位耐力的影响。方法 15名女性青年志愿者经历15 d-6°HDBR,于卧床前1天及卧床后第1天分别接受70°被动立位测试,记录测试全程的心血管血液动力学指标,同时观察血浆肾素活性(PRA)、血管紧张素Ⅱ(ATⅡ)和去甲肾上腺素(NE)含量变化。结果经过15 d头低位卧床后,女性立位耐力不良的发生率为8/15(53.3%)。其中,晕厥前症状中止者为6/15(40.0%),立位后心动过速(POTS)中止者为2/15(13.3%)。立位刺激可引起舒张压、心率和血管总外周阻力明显增加(P<0.05),每博量和心输出量显著降低(P<0.05)。同时,15 d HDBR可显著增加安静平卧位时的舒张压和心率,并减少每博量,但对血管总外周阻力和心输出量的影响并不明显(P>0.05)。立位耐力正常和不良者的差异主要表现为心率(HR)在立位刺激后有明显的增加,组间差异明显。血液生化指标结果显示两组间NE基础水平有显著差异,但在立位刺激下的NE含量的变化幅度未有明显差别(P>0.05)。立位刺激可导致血浆中ATⅡ含量的明显升高,而15 d HDBR则可导致血浆PRA的明显减少(P<0.01)。结论经过15 d头低位卧床后,女性立位耐力不良发生率较高,且存在着不同的表现类型。Objective To explore the effects of 15 d-6° head-down bed rest（HDBR） on female orthostatic tolerance for future countermeasure in outer space. Methods Fifteen female volunteers experienced the 15 d HDBR.They underwent 70° tilting test（TT） on the day before and after HDBR respectively.The blood samples before and after each TT were analyzed for detecting the changes of plasma rennin activity（PRA）,angiotensin Ⅱ（ATⅡ） and noradrenalin（NE） concentration. Results After 15 d HDBR,8/15（53.3%） subjects showed orthostatic intolerance.Among them,6/15（40.0%） experienced cessation of pre-syncope syndrome,2/15（13.3%） experienced cessation of postural tachycardia syndrome（POTS）.The diastolic blood pressure,heart rate（HR） and total peripheral resistance（TPR） increased significantly under TT（P0.05）,whereas the stroke volume（SV） and cardiac output（CO） decreased（P0.05）.The diastolic pressure（DIA） and HR in post-HDBR were higher than those in pre-HDBR,but the TPR and CO were not affected（P0.05）.The main difference between normal group（Normal） and orthostatic intolerance group（OIer） lied in that the HR increment under TT in OIer group was significantly greater than those in normal group.Biochemical blood tests showed that there was significant difference between the two groups in NE baseline level at rest（supine） posture,but no difference in the variation scope of NE level under TT（P0.05）.Plasmic ATⅡ level increased significantly after TT.The PRA was reduced significantly after 15 d HDBR（P0.01）.Conclusion The incidence of OI after HDBR is quite high in female,which is showed in manifestation of diversity.

关 键 词：模拟失重 头低位卧床 立位耐力 血液动力学 

分 类 号：R852.22[医药卫生—航空、航天与航海医学]