摘要
目的探讨反复下体负压暴露对人体下体负压（ＬＢＮＰ） 耐力的影响及其与心血管功能的关系。方法１０ 名男性健康被试者进行负压值为－ ５０ ｍ ｍ Ｈｇ 、持续８ ｍｉｎ 的下体负压锻炼，每天１ 次、连续８ ｄ ，记录心率及血压。锻炼前后进行ＬＢＮＰ 耐力检查，并测量心脏泵血功能。结果锻炼前、后负压最大耐受时间（ＤＮＰ） 及累积应激指数（ＣＳＩ） 分别为：１０５８ ±２１６ ｓ，１３５４ ±２３３ ｓ；４５８３３ ±１２５４６ ｓ·ｍ ｍ Ｈｇ 、６３４３３±１３４５８ ｓ·ｍ ｍ Ｈｇ ，锻炼前后差异显著（ Ｐ＜ ０ ．０５） ，心脏泵血功能呈增强趋势。结论下体负压反复暴露可提高人的下体负压耐力，其原因之一可能在于增强了心肌的收缩能力，降低外周血管的顺应性，心血管系统对低血压应激的代偿机制更加有效，从而提高了心水平动脉血压。
Objective To investigate variation of low body negative pressure(LBNP) tolerance and the relationship with change of heart function after repeated LBNP exposures. Method Ten healthy subjects were exposed to eightmin consecutive daily LBNP (-50 mmHg).Before and after this exposures, tolerance to LBNP was determined by a cumulative stress index (CSI) and duration of negative pressure (DNP). Result The pre and post repeated exposure values of CSI and DNP were 1058±216 s,1354±233 s and 45833±12546 s·mmHg,63433±13458 s·mmHg,respectively.It showed that both were increased significantly (P<0.05),and the heart function was showed to have a tendency of being enhanced.Conclusion It suggested that LBNP tolerance increased after repeated exposures,which might be achieved via strengthening of ventricular contractivity, decreasing the compliance of peripheral vascular,the hypotentive reflex compensatory mechanisms becoming more effective,and increasing arterial blood pressure on heart level.
出处
《航天医学与医学工程》
CAS
CSCD
2000年第1期10-13,共4页
Space Medicine & Medical Engineering
基金
全军"九五"指令性课题!(96L005)
