The clinical significance of disordered renal excretion of xanthurenic acid in depressive patients

Abstract

Xanthurenic acid is a metabolite of L-tryptophanicotinic acid ribonucleotide biosynthesis. The excretion of xanthurenic acid from urine 24 h after ingestion of 5 g L-tryptophan is increased in depressive patients, and 17-hydroxycorticosteroids are considered of primary importance to this disorder. However, in this study, the excretion of xanthurenic acid and 17-hydroxycorticosteroids did not correlate with the scores of the Raskin depression scale, Hamilton depression scale, Zung depression scale, or the Zung anxiety scale in depressive patients. The patients were treated with either pyridoxine plus L-tryptophan, a presumably serotonin-enhancing treatment (n = 10) or maprotiline, a noradrenaline-enhancing drug (n = 10). Repeated measurements showed no differences between treatments after 2 or 4 weeks of treatment. The improvement in xanthurenic acid excretion precedes clinical improvements in depression. The excretion of xanthurenic acid only at 2 weeks correlated significantly with the anxiety and depression scores at 4 weeks, making prediction of clinical improvement possible. The neurobiological mode of action on noradrenergic or serotonergic neurons of antidepressant medication is of questionable significance to their therapeutic effect.

The renal excretion of xanthurenic acid following L‐tryptophan loading in depressed patients

“…Discussion of these differences is rather difficult because Hilgerson (1984) did not mention either the statistical methods used or the composition of his group of psychiatric controls. We did not find differences in XA excretion between major and minor depression, which is in accordance with Hoes (1979), who established no differences in XA excretion between patients suffering from melancholia and those with an adaptation disorder with depressed mood (included in our group of minor depression).…”

“…The renal excretion of xanthurenic acid (XA) following L-tryptophan (L-TRP) loading has been subject to several investigations in the field of depression (Hoes, 1979;Hilgersom, 1984;Maes et al, 1986). Xanthurenic acid is a secondary product of the conversion of L-TRP into nicotinamide.…”

Circulating Antibodies to IDO/THO Pathway Metabolites in Alzheimer's Disease

“…Moreover, Baran et al [30] previously observed that a significant increase in Kyna production in the putamen and caudate nucleus of AD patients was associated with an elevated kynurenine metabolism. Xantha production via the IDO-1 pathway is higher in depressed patients than controls [31] and plays a role in apoptosis [32], as well as acting as a neuromodulator in the rat brain [33]. The production of 3-OH anthra, Anthra, and Pico in AD had not previously been studied in sufficient detail.…”

Anxiety Disorders: Sex Differences in Serotonin and Tryptophan Metabolism

“…This is important as kynurenine and quinolinic acid (QA) possess anxiogenic effects. Similarly, higher levels of kynurenine and excreted xanthurenic acid (XA) were found to be positively correlated to levels of anxiety [88,89]. Lapin et al (1996) [90] found that QA reduced the duration of social interaction, as well as grooming behavior, in mice and is therefore inferred to have anxiogenic effects.…”