Tryptophan disposition in psychiatric patients before and after stress

Abstract

SynopsisNon-esterified fatty acid and total and free tryptophan were determined in the plasma of psychiatric patients unselected with respect to psychiatric diagnosis and in the plasma of normal subjects before and after physiological and psychiatric tests. Retarded patients had significantly low total and free tryptophan values which correlated negatively with agitation. Total tryptophan fell significantly after testing in the non-retarded subjects. The only biochemical abnormality significantly associated with a diagnosis of primary depression was the rise of plasma non-esterified fatty acid after testing. Thus, tryptophan abnormalities were associated more with psychiatric rating scores than with diagnoses.

IDO chronic immune activation and tryptophan metabolic pathway: A potential pathophysiological link between depression and obesity

“…Tryptophan levels are significantly reduced in depressed patients (Joseph et al, 1984;Maes et al, 1987aMaes et al, , 1987bMaes et al, , 1990aMaes et al, , 1991bCapuron et al, 2011b;Liu et al, 2015b). In these patients, TRY plasma levels may be inversely associated with severity of depression, anxiety, somatization, suicidal ideation, neuromuscular symptoms and paranoia (Lehmann, 1972;Curzon et al, 1979;Joseph et al, 1984;Capuron et al, 2011b;Maes et al, 2011b;Blankfield, 2013;Flores-Ramos et al, 2014;Gostner et al, 2015;Hüfner et al, 2015). Besides this, TRY plasma levels may constitute a predictor of therapeutic response to serotonergic antidepressants, particularly selective inhibitors of the 5-HT uptake (Møller, 1985).…”

The Biology of Manic Depressive Illness (The Ole Rafaelsen Memorial Lecture)

“…Tryptophan is bound to albumin in the plasma, and the free (non-bound) fraction is only 10 to 20% of the total plasma tryptophan There are several reports of lowered concentrations of free tryptophan in depression (14,15,16,17), although others have reported normal levels (18). There are a number of possible explanations for these discrepancies in the reported level of free tryptophan in depression.…”

Transmitter amines in depression

“…which can compete with its uptake by the brain (Moller et al 1980). Although low plasma tryptophan in depression could be primarily a consequence of depressive symptoms (Curzon et al 1979;Shaw et al 1980), it might nevertheless alter the course of the illness.…”