Motilin

Definition

Motilin is a peptide hormone that plays a crucial role in regulating gastrointestinal motility. It is secreted by the M cells in the small intestine and stimulates the contraction of smooth muscle in the gastrointestinal tract, promoting peristalsis and facilitating the movement of food through the digestive system. This hormone is particularly important during fasting states, as it helps coordinate the migrating motor complex, which cleanses the intestines.

5 Must Know Facts For Your Next Test

1. Motilin levels increase during fasting and peak just before meals, indicating its role in preparing the digestive system for food intake.
2. The release of motilin triggers phase III of the migrating motor complex, which helps to clear residual undigested material from the gastrointestinal tract.
3. Motilin acts on specific receptors in the smooth muscle of the gastrointestinal tract, promoting contractions that enhance motility.
4. Disruptions in motilin secretion or function can lead to gastrointestinal disorders such as gastroparesis or irritable bowel syndrome.
5. In addition to its primary role in motility, motilin may also influence appetite regulation and gut-brain communication.

Review Questions

• How does motilin interact with other hormones in regulating gastrointestinal function?
  • Motilin works in concert with other hormones like gastrin and cholecystokinin to regulate gastrointestinal function. While motilin specifically enhances motility by promoting smooth muscle contractions, gastrin increases gastric acid secretion to aid digestion, and CCK facilitates bile release for fat digestion. Together, these hormones create a coordinated response to food intake and ensure efficient digestion.
• Discuss how disruptions in motilin secretion might impact digestive health.
  • Disruptions in motilin secretion can lead to various digestive health issues, such as gastroparesis, where delayed gastric emptying causes symptoms like nausea and bloating. Low levels of motilin may hinder effective intestinal movement, leading to constipation or other functional gastrointestinal disorders. Understanding these connections helps highlight the importance of maintaining proper hormonal balance for optimal digestive health.
• Evaluate the implications of motilin as a therapeutic target for gastrointestinal disorders.
  • Motilin has emerged as a potential therapeutic target for treating various gastrointestinal disorders due to its role in enhancing gut motility. Research into motilin agonists shows promise for conditions like gastroparesis, where improving intestinal movement can alleviate symptoms. However, further studies are needed to understand its broader effects and potential side effects, ensuring that treatments targeting motilin effectively improve patient outcomes without causing adverse reactions.

Related terms

Gastrin: A hormone produced by G cells in the stomach that stimulates gastric acid secretion and promotes gastric motility.

Cholecystokinin (CCK): A hormone released by the small intestine that stimulates gallbladder contraction and the release of digestive enzymes from the pancreas.

Ghrelin: A hormone produced primarily in the stomach that stimulates appetite and promotes food intake, often referred to as the 'hunger hormone.'