[Biochemical evaluation of various respiration conditions during simulation of extended flight].

During a simulated long-term mission with participation of male volunteers biochemical effects of various conditions of oxygen supply including breathing the cabin air at 2.4 km, pure oxygen, and intermittent hypoxia/hyperoxia, i.e. breathing the cabin air for 50 min and pure O2 for 10 min every hour in flight were studied. This assessment of respiration conditions by biochemical criteria allowed to recognize the combination of short hyperoxia and cabin air as the optimum to be taken into accounted in attacking the problem of oxygen supply of aviators in extended flights.