Effect Of Psychological Stress On Lung Injury Induced By Simulated Acute High-altitude Hypobaric Hypoxia In Rat

Background and purposeHypobaric hypoxia environment in high-altitude is the fundamental cause of acute high altitude sickness. Fast getting to high altitude, cold weather, individual fatigue, infections of respiratory tracts and psychological stress are important factors to urge or induce acute high altitude sickness. Up till now, the research on the pathomechanism of psychological stress to urge or induce acute high altitude sickness is still lack. Therefore, we examined the effect of psychological stress on lung injury induced by simulated acute high- altitude hypobaric hypoxia in rats, and measured the hippocampal extracellular monoamine level, in order to investigate the relationship between the lung injury and the monoamine metabolism in central nervous system.MethodMale SD rats were randomly divided into ten groups: control (Con group), hypoxia (Hy group), psychological stress (twice daily×1day) (Ps1group), psychological stress (twice daily×2day) (Ps2 group), psychological stress (twice daily×1day) + hypoxia (Ps1+Hy group), psychological stress (twice daily×2day) +hypoxia (Ps2+Hy group), physiological stress (twice daily×1day) (Ph1group), physiological stress(twice daily×2day) (Ph2group), physiological stress (twice daily×1day) + hypoxia (Ph1+Hy group), physiological stress (twice daily×2day) + hypoxia (Ph2+Hy group). The acute hypobaric hypoxia disposure was made by putting the rats into hypobaric chamber at a simulated altitude of 6000 meters for 24 hours. Psychological and physiological stress all used the way of communication box (CB). The extracellular fluid of hippocampus was collected by the push-pull perfusion method. The contents of norepinephrine (NE), dopamine (DA), 3, 4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), 5-hydroxytryptamine (5-HT), and 5-hydroxy- indole-3-acetic acid (5-HIAA) in the extracellular fluid of hippocampus were determined by high performance liquid chromatography with electrochemical detection (HPLC-ECD). The level of plasma corticosterone was determined by radioimmunoassay. To assess the...