Experimental validation for development of medical technology of oxidative stress (lipid peroxidation) non-invasive diagnosis during space flight

摘要

As human's duration of stay in space will get longer and with perspectives of interplanetary missions, noninvasive online methods of integral diagnosis of crewmembers' physiological status will be the basis of space medicine. The goal of this study is to develop medical technology for non-invasive diagnosis of lipid peroxidation activity during physiological adaptation of human to the conditions of space flight. The basis for this medical technology is research of low-molecular weight metabolites - biomarkers of lipid peroxidation in the human breath which will allow to monitor the molecular metabolites during space flight online and to evaluate in real time: the processes of lipid peroxidation by biomarkers in breath and to diagnose functional metabolic status of cosmonauts; activity of lipid peroxidation processes in the body before and after extra-vehicular activity and to perform medical correction of oxidative stress in real time (if needed) with an estimation of the prevention measures' efficiency. Experimental research was made in order to determine a list of molecular metabolites in breath of volunteers during simulation of lipid peroxidation activity by exposure to normobaric hyperoxygination, zero-g conditions (dry immersion) and graduated exercise. It was shown by simulation of oxidative stress by stress tests (breathing 100% oxygen during 1 hour and physical exercises on stationary bicycle) that the activation of lipid peroxidation (which was confirmed by changes of MDA in blood) isan integral indicator of metabolic processes and that an imbalance in regulation of red-ox processes in cells is accompanied by an increase of lipid peroxidation biomarkers concentration in the human breath. The experiments mentioned above allowed determining the list of volatile metabolites, which showed concentration increase in 90% and 80% of breath samples. The list of lipid peroxidation biomarkers to be detected: ethane, pentane, propane, 3-methylhexane, 2-methylpentane,