5-Hydroxytryptophan-induced cortisol response and CSF 5-HIAA in depressed patients

Abstract

To determine if the enhanced cortisol response to oral administration of the serotonin (5-HT) precursor 5-hydroxytryptophan (5-HTP) that has been reported in unmedicated depressed and manic patients might be related to brain monoaminergic metabolism, the authors assessed correlations between 5-HTP-induced cortisol response and CSF in nine depressed patients. They found a significant negative correlation with CSF levels of 5-hydroxyindoleacetic acid, a 5-HT metabolite, but not with CSF levels of other monoamine metabolites. This finding is consistent with the hypothesis that low presynaptic brain serotonergic activity may be related to enhanced cortisol response to 5-HTP in depressed patients.

Serotonin Transporter Deficiency Induces Metabolic Alterations in the Ileal Mucosa

“…SERT is expressed in epithelial cells, neurons, immune cells, and platelets [11,12]. As such, SERT has been implicated in several neurological and neuropsychiatric disorders, such as depression, Alzheimer's, Parkinson's disease, autism, ADHD, bipolar disorder, Tourette's syndrome, visceral pain, and anxiety [6,[13][14][15]. More specifically, intestinal epithelial cell SERT has been implicated in several disease states related to intestinal inflammation, such as enteric infections, animal models of colitis/ileitis, and inflammatory bowel disease (IBD) [16][17][18][19].…”