Motilin

Motilin is a 22-amino acid polypeptide hormone that is secreted by the M cells in the small intestine, specifically in the duodenum and jejunum. It plays a crucial role in gastric motility and the regulation of interdigestive gastrointestinal motility.

Function

Motilin is released every 80-120 minutes during a fasting state, and its release is triggered by a drop in gastric pH to 3 or lower. This release initiates the migrating motor complex (MMC), a series of contractions in the intestines that clear out undigested material.

Motilin's role in stimulating the MMC is important for the overall health of the gastrointestinal tract. It helps to prevent bacterial overgrowth and promotes the absorption of nutrients in the intestines.

Clinical significance

Abnormal levels of motilin can lead to a variety of gastrointestinal disorders, including gastroesophageal reflux disease (GERD), irritable bowel syndrome (IBS), and functional dyspepsia.

Motilin agonists, such as erythromycin, are used to stimulate gastrointestinal motility in patients with gastroparesis. Conversely, motilin antagonists can be used to slow down the gastrointestinal tract in conditions such as diarrhea.

See also

• Gastrointestinal hormones
• Migrating motor complex
• Gastrointestinal motility

Motilin

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