Plasma tryptophan to large neutral amino acids ratio and therapeutic response to a selective serotonin uptake inhibitor.
The molar ratio of total plasma tryptophan (Trp) to the sum of the other large neutral amino acids (LNAAs), thought to reflect brain serotonin (5-HT) formation, was estimated in 47 patients with major depression (unipolar and bipolar) before and after 6 weeks of treatment with a serotonin uptake inhibitor, fluvoxamine. We found a significant difference between responders (n = 39) and nonresponders (n = 8) for the pre- and in-treatment plasma Trp to LNAAs ratios. In contrast, there were no differences between the two groups for the mean plasma steady-state fluvoxamine levels. These findings suggest that a specific plasma amino acid profile may be a useful indicator of good clinical response to a selective 5-HT uptake inhibitor.
Istituto di Ricovero e Cura a Carattere Scientifico H. San Raffaele, Italia.
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Smeraldi
D000328:Adult; D000368:Aged; D000596:Amino Acids / Q000097:blood*; D001714:Bipolar Disorder / Q000097:blood / Q000188:drug therapy* / Q000523:psychology; D003866:Depressive Disorder / Q000097:blood / Q000188:drug therapy* / Q000523:psychology; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D016666:Fluvoxamine / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010555:Personality Inventory; D014364:Tryptophan / Q000097:blood*
D000596:Amino Acids; D014364:Tryptophan; D016666:Fluvoxamine