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Brain tryptophan and the neoplastic anorexia‐cachexia syndrome
Author(s) -
Krause Rudolf,
Howard James J.,
Ziparo Vincenzo,
Fischer Josef E.
Publication year - 1979
Publication title -
cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.052
H-Index - 304
eISSN - 1097-0142
pISSN - 0008-543X
DOI - 10.1002/1097-0142(197909)44:3<1003::aid-cncr2820440330>3.0.co;2-3
Subject(s) - anorexia , endocrinology , medicine , tryptophan , serotonergic , cachexia , serotonin , metabolism , neurotransmitter , central nervous system , amino acid , biology , biochemistry , cancer , receptor
The cause of anorexia associated with neoplasia is unknown, and some investigators have suggested a central mechanism. Recent neurophysiologic studies have revealed the possible role of serotoninergic system involving tryptophan (TRP) and its indole neurotransmitter metabolites in regulating particular aspects of feeding behavior. We therefore studied plasma and brain factors affecting TRP transport through the blood‐brain barrier (plasma free and total TRP, albumin, nonesterified fatty acids, plasma neutral amino acids, brain uptake index [BUI] for TRP) and central serotonin metabolism (5‐HT, 5‐HIAA) in young, anorexic rats bearing the Walker‐256 tumor injected intramuscularly. Plasma free TRP, but not plasma total TRP, and, more important, brain TRP and brain 5‐HIAA were significantly higher in tumorbearing rats than in pair‐fed control animals. The results suggest an association between altered brain TRP metabolism and feeding behavior in tumorrelated anorexia.