Serotonin signalling in the gut—functions, dysfunctions and therapeutic targets

Summary & key facts

This paper is a review of many studies about serotonin in the gut. Serotonin is a chemical made mostly in the gut that helps control bowel movement, fluid secretion and blood flow there. It also sends messages to the brain that can cause nausea, fullness after eating, and abdominal pain. The authors describe how gut serotonin can promote inflammation, help gut nerve cells survive and regrow, and affect platelets in the blood. They also explain that some existing drugs work by blocking or activating specific serotonin receptors in the gut, and that new treatments that act only on the gut lining might be safer.

Key facts:

• Most of the body's serotonin is made in the gut by special cells called enterochromaffin cells, not in the brain.
• When serotonin is released in the gut it helps push food along, causes mixing movements, and makes the gut secrete fluid and widen blood vessels.
• Serotonin in the gut can activate nerves that send signals to the brain. Those signals can slow stomach emptying, make you feel full, cause nausea, and contribute to abdominal pain or discomfort.
• Gut-derived serotonin can promote inflammation in the intestine in some conditions, according to studies reviewed by the authors.
• Serotonin in the muscle layers of the gut supports the survival and repair of gut nerve cells and of interstitial cells of Cajal, which help coordinate gut rhythms.
• Drugs that block one type of serotonin receptor (called 5-HT3) have been used for diarrhoea-related disorders, while drugs that activate another type (called 5-HT4) have been used for constipation-related disorders.
• The authors say there is growing interest in drugs that work only on the gut lining and are not absorbed into the body, because these might treat gut problems with fewer side effects.

Topics

Biochemical Analysis and Sensing Techniques Gastrointestinal motility and disorders Respiratory and Cough-Related Research

Categories

Gastroenterology Health Sciences Medicine

Tags

5-HT receptor Biology Immunohistochemistry Internal medicine Interstitial cell of Cajal Irritable bowel syndrome Medicine Neuroscience Receptor Reflex Serotonergic Serotonin Stimulation Tegaserod

Conditions & symptoms

Chronic Pain Chronic pain Poor appetite or overeating