Problems in analysis of data from muscles of rats flown in space.
Comparison of hindlimb muscles of rats flown on Spacelab-3 or tail-traction-suspended showed that 11-17 h reloading post-flight might have altered the results.  Soleus atrophied, plantaris, gastrocnemius and extensor digitorum longus grew slower, and tibialis anterior grew normally.  In both flight and simulated soleus and plantaris, higher tyrosine and greater glutamine/glutamate ratio indicated negative protein balance and increased glutamine production, respectively, relative to controls.  Aspartate was lower in these muscles.  Reloading generally decreased tyrosine, but increased aspartate and glutamine/glutamate.  These data showed that at 12 h of reloading after flight is characterized by reversal to varying extents of effects of unloading.
Tischler
M E
ME
Department of Biochemistry, University of Arizona Health Sciences Center, Tucson 85724, USA.
Henriksen
E
E
Jacob
S
S
Satarug
S
S
Cook
P
P
D000222:Adaptation, Physiological; D000600:Amino Acids, Dicarboxylic / Q000378:metabolism; D000818:Animals; D005650:Fumarates / Q000378:metabolism; D006003:Glycogen / Q000378:metabolism; D019417:Hindlimb Suspension; D008297:Male; D009124:Muscle Proteins / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism*; D009133:Muscular Atrophy; D051381:Rats; D012107:Research Design / Q000706:statistics & numerical data; D013026:Space Flight; D013623:Tail; D014443:Tyrosine / Q000378:metabolism; D014893:Weightlessness; D018474:Weightlessness Simulation
D000600:Amino Acids, Dicarboxylic; D005650:Fumarates; D009124:Muscle Proteins; D014443:Tyrosine; C032005:fumaric acid; D006003:Glycogen