Studies of amino acid metabolism in the muscles of rats flown aboard the biosatellite Cosmos 782.
Space flight induced an increase in the content of free isoleucine, leucine, phenylalanine, tyrosine, and valine and a decrease of free threonine and glycine in the quadriceps muscle of the rat. The content of the individual free amino acids returned to their control values by the 25th postflight day. The total content of free amino acids remained unaltered from the control values. In the ground-based synchronous experiment the content of most free amino acids increased on the first and decreased on the 25th post-experimental day. These findings suggest that weightlessness induces development of protein catabolism in muscular tissue. However, the developments are compensatory with respect to total free amino acid content.
Ushakov
A S
AS
Institute of Biomedical Problems, USSR Ministry of Health, Moscow.
Vlasova
T F
TF
Miroshnikova
E B
EB
D000222:Adaptation, Physiological; D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D008297:Male; D009124:Muscle Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000201:enzymology* / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013026:Space Flight; D014893:Weightlessness
D000596:Amino Acids; D009124:Muscle Proteins