Amino acids, serotonin, and 5-hydroxyindoleacetic acid following foot shock in rats.
Concentrations of tryptophan, serotonin (5-HT), and 5-hydroxyindoleacetic acid (5-HIAA) in brain and plasma, as well as plasma amino acid composition, were measured after 1-h foot shock. Stress induced a rise in both plasma and brain 5-HIAA, whereas 5-HT concentration was found to be increased only in plasma. A prominent rise in brain tryptophan was observed, whereas in plasma, foot shock caused a significant increase only in tryptophan level. Concentrations of other amino acids were found to be either decreased or unchanged. Ratio of tryptophan to the other long-chain neutral amino acids increased significantly following foot shock. It is possible that stress-related changes in 5-HT turnover are due to increased plasma tryptophan, in turn causing a rise in brain tryprophan, necessary to cope with enhanced 5-HT metabolism, reflected as a rise in 5-HIAA levels.
Malyszko
J
J
Department of Physiology, Hamamatsu University School of Medicine, Shizuoka, Japan.
Urano
T
T
Takada
Y
Y
Takada
A
A
D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D001769:Blood / Q000378:metabolism; D004597:Electroshock; D005528:Foot; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism*; D008297:Male; D009994:Osmolar Concentration; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000378:metabolism*
D000596:Amino Acids; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid