Oxidative phosphorylation in rat skeletal muscles after space flight on board biosatellites.

Polarographic analysis of biological oxidation in rat's skeletal muscles after the 18- and 22-day flights revealed changes specific for the flight animals: oxidative phosphorylation uncoupling, distinct inertness of energy accumulation after 10 hrs of landing. Tissue respiration's inhibition was observed in both flight and synchronous rats suggesting the effect of other than microgravity factors. Energy metabolism in muscles of flight animals returned to the pre-flight level later (29 d) compared to the synchronous rats (6 d). Muscles of different functions (predominance of fast or slow fibers) showed similar responses of energy metabolism to weightlessness, i.e. inhibition of the intensity and decline of the energy efficiency of oxidative processes. A decrease in dehydrogenase activity has been found in the first day of recovery. The effects may be caused by the inhibition of both aerobic and anaerobic metabolism after space flight.