Nesterov V P, Zheludkova Z P, Kuznetsova L A
Sechenov Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences USSR, Leningrad, USSR.
Acta Astronaut. 1979 Oct;6(10):1305-11. doi: 10.1016/0094-5765(79)90122-x.
The effect of a 20-day space flight on water, Na+, K+, Mg2+, Ca2+ and glycogen contents as well as on activities of glycogen metabolism enzymes--glycogen synthetase and glycogen phosphorylase--of rat skeletal muscles was studied. This data is regarded as an integral test characterizing the state of contractile tissue of the animals at the final stage of flight aboard biosatellites. The measurements indicate that there were no significant changes of cations and glycogen contents nor of the enzymic activities in fast-twitch muscles during the 20-day spaceflight. At the same time dehydration in these muscles was observed, which disappeared on the 25th postflight day. In slow-twitch antigravitational skeletal muscle (m. soleus) there was a decrease of K+ and increase of Na+ in the tissue contents. The changes disappeared at the end of the on-earth readaptation period. From the pattern of these observations, we can conclude that the 20-day space flight leads to some reversible biochemical changes of the rat skeletal muscles. A conclusion can be drawn about necessity of creating, aboard the spaceship, an artificial load on antigravitational skeletal muscles.
研究了为期20天的太空飞行对大鼠骨骼肌中水、Na⁺、K⁺、Mg²⁺、Ca²⁺和糖原含量以及糖原代谢酶——糖原合成酶和糖原磷酸化酶活性的影响。这些数据被视为表征动物在生物卫星上飞行最后阶段收缩组织状态的综合测试。测量结果表明，在为期20天的太空飞行期间，快肌中的阳离子和糖原含量以及酶活性均无显著变化。同时观察到这些肌肉出现脱水现象，该现象在飞行后第25天消失。在慢肌抗重力骨骼肌（比目鱼肌）中，组织中的K⁺含量降低，Na⁺含量升高。这些变化在地面再适应期结束时消失。从这些观察结果模式可以得出结论，为期20天的太空飞行会导致大鼠骨骼肌发生一些可逆的生化变化。可以得出结论，在宇宙飞船上有必要对抗重力骨骼肌施加人工负荷。
