Tryptophan hydroxylase 1 enzyme (TPH1)

Tryptophan hydroxylase 1 enzyme (TPH1) is the rate-limiting enzyme responsible for the synthesis of serotonin (5-hydroxytryptamine, 5-HT) in enterochromaffin cells of the gastrointestinal tract[2][3]. This enzyme catalyzes the conversion of tryptophan to 5-hydroxytryptophan, which is then converted to serotonin. About 90% of the body's serotonin is synthesized in the gut, and TPH1 controls this pathway[3]. The activity of TPH1 and the abundance of serotonin in the gut are strongly influenced by gut microbiota composition and metabolic activity[2][3]. Changes in serotonin production via TPH1 are linked to a range of functions including gastrointestinal motility, immune regulation, and communication along the gut-brain axis, implicating TPH1 in the pathogenesis of disorders such as inflammatory bowel disease, IBS, and depression[1][3]. Pharmacological inhibitors of TPH1, such as telotristat, are used to reduce peripheral serotonin levels in certain conditions.

Other names

TPH1Tryptophan hydroxylase type 1TPHTRP hydroxylase 1

Enzyme inhibition (modulation of serotonin synthesis by inhibiting TPH1 in enterochromaffin cells)