Investigating Serotonin Signalling in IBD Patients

The gut produces approximately 95% of serotonin (5-hydroxytryptamine; 5-HT) found in the human body; where, it is a very important mucosal signaling molecule participating in gut motility, sensation, and secretion.The vast majority of the gut-derived 5-HT is produced by specialized epithelial cells of The GI tract, called enterochromaffin (EC) cells. EC cells produce 5-HT from dietary tryptophan, this process involves the rate limiting enzyme tryptophan hydroxylase (TPH) 1, once produced this 5-HT can be released into the gut lumen, surrounding tissue and can enter the blood circulation.5-HT mediates many gastrointestinal functions, including secretion and peristalsis, by acting on a diverse range of 5-HT receptors. Five of the seven known receptor families of 5-HT (5-HT1, 5-HT2, 5-HT3, 5-HT4 and 5-HT7) are expressed in the gut.

5-HT has been evaluated in IBD and in animal models of colitis. An increase in numbers of EC cells expressing 5-HT is observed in CD and UC patients and consumption of selective 5-HT reuptake inhibitors is associated with microscopic colitis. In the present study, we plan to investigate the key elements of mucosal 5-HT signaling in CD patients for a better understanding of the role of 5-HT in pathogenesis of IBD.

Inclusion criteria

• Patient groups: Disease diagnosis (CD or UC),duration of disease, previous/type of treatments, duration of treatment and disease prognosis.
• Healthy controls: No diagnosis of CD or UC and no diagnosis of IBS.

Exclusion criteria

• Patient groups: Drugs that directly affect components of 5-HT signaling, any other disease or condition that may interfere with study assessments as judged by the investigator.
• Healthy controls:Chronic use of any anti-inflammatory drugs, drugs that directly affect components of 5-HT signalling and any other disease or condition that may interfere with study assessments as judged by the investigator.