The effect of tryptophan deficiency in the brain on rat fatigue levels: a rat model of fatigue reduction.
The level of tryptophan and 5-hydroxyindoleacetic acid were measured in the brain (striatum) of rats on tryptophan-deficient diet and tryptophan-enriched diet. We measured concentrations of tryptophan and 5-hydroxyindoleacetic acid in striatum by using microdialysis and HPLC methods. The extracellular level of tryptophan and 5-hydroxyindoleacetic acid concentration in the striatum of a tryptophan-reduced rats was decreased by about 50% compared with a tryptophan-enriched diet. In the tryptophan-reduced condition, the rats an increased the running time of more than 100 min, compared with those on a tryptophan-enriched diet. These results suggest the tryptophan and 5-hydroxytryptamine in the central nervous system are involved in fatigue.
Yamamoto
Takanobu
T
Health Science Laboratory, Tezukayama University, Tezukayama 7-1-1, Nara, Japan. yamamoto@tezukayama-u.ac.jp
Newsholme
Eric A
EA
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism; D005221:Fatigue / Q000209:etiology / Q000378:metabolism* / Q000517:prevention & control; D005260:Female; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014364:Tryptophan / Q000008:administration & dosage / Q000172:deficiency*
D006897:Hydroxyindoleacetic Acid; D014364:Tryptophan