Portugalov V V, Gorbunova A V, Petrova N V
Biol Bull Acad Sci USSR. 1979 Jan-Feb;6(1):11-9.
The stage of structures of the spinal reflex arc was studied by methods of quantitative cytochemistry in rats after orbital space flights lasting 19.5 and 22.5 days; the RNA and cytoplasmic protein content was determined in spinal motoneurons and sensory neurons of the spinal ganglia, the composition of soluble proteins of the gray and white matter of the spinal cord and spinal ganglia was determined; the lactate dehydrogenase (LD) isozyme spectrum also was investigated in the spinal ganglia and muscles of the hind limbs. A decrease in the content of cytoplasmic proteins in the spinal motoneurons and neurons of the spinal ganglia and a decrease in the content of water-soluble proteins in the gray and white matter of the spinal cord were found 5-11 h after space flight lasting 19.5 days and during the first day after a space flight lasting 22.5 days. Significant changes in the activity of isozyme fractions LD1 and LD2 were found in homogenates of the spinal ganglia. On the 1st and 2nd days after flight the LD isozyme spectrum of the soleus muscle changed from "cardiac" to "intermediate" type. The changes discovered were evidently the result of functional underactivity of the skeletal muscles under conditions of weightlessness. An increase in the RNA content in the sensory and motor neurons and an increase in the content of water-soluble proteins in the gray matter of the spinal cord were found 25-27 days after the end of the space flights, probably a manifestation of readaptation of the animals to terrestrial conditions.
采用定量细胞化学方法，对经历了19.5天和22.5天轨道太空飞行后的大鼠脊髓反射弧结构阶段进行了研究；测定了脊髓运动神经元和脊髓神经节感觉神经元中的RNA和细胞质蛋白含量，确定了脊髓和脊髓神经节灰质和白质中可溶性蛋白的组成；还研究了脊髓神经节和后肢肌肉中的乳酸脱氢酶（LD）同工酶谱。在持续19.5天的太空飞行后5 - 11小时以及持续22.5天的太空飞行后的第一天，发现脊髓运动神经元和脊髓神经节神经元中的细胞质蛋白含量下降，脊髓灰质和白质中的水溶性蛋白含量下降。在脊髓神经节匀浆中发现同工酶组分LD1和LD2的活性有显著变化。飞行后第1天和第2天，比目鱼肌的LD同工酶谱从“心脏型”转变为“中间型”。所发现的这些变化显然是失重条件下骨骼肌功能活动不足的结果。在太空飞行结束后25 - 27天，发现感觉神经元和运动神经元中的RNA含量增加，脊髓灰质中的水溶性蛋白含量增加，这可能是动物重新适应地面条件的一种表现。
