模拟微重力对热应激时人血浆中单胺类递质含量的影响

EFFECTS OF SIMULATED MICROGRAVITY ON THE CONTENTS OF MONOAMINE TRANSMITTERS IN HUMAN PLASMA DURING HEAT STRESS

目的和方法 :采用高效液相色谱 -电化学检测法 ,分析 7d - 6°头低位卧床模拟微重力 ,40～ 6 0℃热应激及其复合因素作用下人外周血中单胺类递质的含量 ,研究模拟微重力对热应激时人外周血中单胺类递质含量的影响 ,以探讨航天热应激的人体反应机理。结果 :①模拟微重力单一因素暴露后 ,5 HT ,NE ,E含量与对照组相比均无显著变化 (P >0 .0 5 ) ;②热应激单一因素暴露 :40℃ ,5 0℃ ,6 0℃热应激时 ,与对照组相比 ,5 HT含量均显著降低 (P <0 .0 1) ,而NE ,E含量 ,在 40℃热应激时无显著变化 (P >0 .0 5 ) ,5 0℃ ,6 0℃热应激时均显著增加 (P <0 .0 0 1) ;③热应激与模拟微重力复合因素暴露时 ,与对照组相比 ,5 HT含量显著降低 (P <0 .0 1) ,而NE ,E含量均无显著变化 (P>0 .0 5 )。与热应激单一因素暴露组相比 ,5 0℃ ,6 0℃热应激时 ,NE ,E含量均显著降低 (P <0 .0 0 1) ,5 HT的含量则无显著变化 (P >0 .0 5 )。结论 :模拟微重力可使热诱导的NE ,E含量显著降低 ,而对热应激引起的 5 HT含量降低无显著影响。模拟微重力引起热应激时NE ,E含量显著降低的变化 。

Aim and Methods:Using high performance liquid chromatography electrochemistry detection method to study the effects of simulated microgravity of a 7 day bed rest in -6° head down title(HDT) position,heat stress and their combination on the contents of monoamine transmitters in human plasma,the aim of the present study is to examine effects of simulated microgravity on the contents of monoamine transmitters during heat stress and to investigate the mechanism of human responses to heat stress in spaceflight.Results:①The content of 5 HT,NE,E did not change significantly( P >0.05) after simulated microgravity alone.②Exposed to heat stress alone,the content of 5 HT produced a marked decrease( P <0.01) at ≥40℃,while the contents of NE,E had manifested increases( P <0.01) at ≥50℃.③Under the effect of the combination of simulated microgravity and heat stress,compared with control group,there was a significant decrease in the content of 5 HT ( P <0.01),but NE,E did not change significantly( P >0.05).Compared with heat stress alone,there was a significant decrease in the content of NE,E( P <0.001),while 5 HT did not change significantly ( P >0.05).Conclusion:Simulated microgravity decreased the content of heat induced NE,E,significantly,and the suppression probably plays an important role in degraded human responese to heat stress in spaceflight.