[Imbalances of neutral plasma amino acids as a pathogenetic factor in anorexia].
Studies in anorectic tumor-bearing rats indicate that anorexia is correlated to imbalances of neutral amino acids in blood and CNS. Consequently plasma amino acids of patients with neoplastic and non-neoplastic internal diseases were studied during phases of anorexia; special regard was given to the precursors of dopamine and serotonin. Anorectic patients were compared to non-anorectic patients with neoplasia. During anorexia, plasma levels of valine and leucine and hence the ratio of the molar concentrations of Val + Leu + Ile/Phe + Tyr were significantly decreased in each anorectic patient as compared to non-anorectic patients whose ratios were always within the normal ranges. As aromatic and branched-chain amino acids compete for penetration of the blood brain barrier, the decrease of the amino acid ratio may induce a raised flux of phenylalanine and tyrosine into the CNS which results in an increased activation of dopaminergic neurons--known to cause anorexia.
D000597:Amino Acids, Branched-Chain / Q000097:blood*; D000855:Anorexia / Q000097:blood*; D001068:Feeding and Eating Disorders / Q000097:blood*; D006801:Humans; D007930:Leucine / Q000097:blood; D007951:Leukemia, Myeloid / Q000097:blood; D011954:Receptors, Dopamine / Q000378:metabolism; D014364:Tryptophan / Q000097:blood; D014633:Valine / Q000097:blood
D000597:Amino Acids, Branched-Chain; D011954:Receptors, Dopamine; D014364:Tryptophan; D007930:Leucine; D014633:Valine
Imbalanzen neutraler Plasma-Aminosäuren als pathogenetischer Faktor der Anorexie.