摘要
目的观察 2 1d头低位卧床期间脑血流的变化及最后一周下体负压对抗的影响。方法 1 2名健康男性志愿者 ,随机分为对照组和LBNP组 ,每组 6人 ,进行头低位倾斜卧床 ( - 6°)。对照组在卧床期间不做任何处理 ,LBNP组在卧床最后一周 ,每天进行 1h、- 4.0kPa的下体负压锻炼。利用KYENG Ⅰ导纳式双侧脑血流自动检测仪测量卧床前、卧床第 3、1 0及 2 1天的脑血流量。结果对照组的左侧大脑Ⅰ相面积及流入速度在卧床期间较卧床前均显著降低 ,左侧大脑主峰高度在卧床第 3及 2 1天显著降低 ,左侧大脑阻力指数在卧床第 3及 2 1天显著升高 ;LBNP组的左侧大脑Ⅰ相面积在卧床第 3及 2 1天较卧床前均显著降低 ,左侧大脑阻力指数在卧床期间均显著升高 ,左侧大脑主峰高度及流入速度在卧床第 3及 2 1天有降低趋势 ,但未达到显著水平。两组之间比较无显著性差异。结论 2 1d头低位卧床可引起脑血管阻力增加 ,脑血流量减少 ;在 2 1d头低位卧床的最后一周进行下体负压锻炼 ,不能有效地对抗头低位卧床模拟失重引起的脑血流的变化。
Objective To investigate the changes of cerebral blood flow(CBF) during 21 d head down tilt (HDT)bed rest and the effect of lower body negative pressure(LBNP) in the last week. Method Twelve healthy male subjects were randomly divided into control and LBNP groups, with 6 in each group. All of them were exposed to -6°HDT for 21 d. The LBNP group received -4.0 kPa LBNP training 1 h/d in the last week of HDT while the control group did not. CBF and cerebral vascular resistance were measured by rheoencephalogram in pre HDT, day 3, 10 and 21 of HDT. Result In control group, left cerebral I quadrant area and inrush velocity decreased significantly during HDT, and left cerebral ΔGy wave crest height decreased significantly, whereas left cerebral resistance index increased significantly on day 3 and 21 of HDT as compared to those of pre HDT.In LBNP group,left cerebral I quadrant area decreased significantly, and left cerebral ΔGy wave crest height and inrush velocity tended to decrease on day 3 and 21 of HDT,whereas left cerebral resistance index increased significantly during HDT as compared to those of pre HDT.There were no significant differences between above indexes in control group and LBNP group. Conclusion It is suggested that 21 d HDT may increase cerebral vascular resistance and decrease CBF, which can not be prevented by LBNP training in the last week of 21 d HDT.
出处
《航天医学与医学工程》
CAS
CSCD
北大核心
2001年第2期92-96,共5页
Space Medicine & Medical Engineering
基金
国家 8 63资助项目!( 863 2 4 2 4)
关键词
下体负压
失重模拟
脑血流
导纳
卧床实验
lower body negative pressure
weightlessness simulation
cerebral blood flow
admittance
bed rest
