Gastrin

Definition

Gastrin is a hormone produced by G cells in the stomach lining that stimulates the secretion of gastric acid, aiding in digestion. It plays a crucial role in enhancing digestive processes by promoting the release of enzymes and acid that break down food. Additionally, gastrin is involved in the regulation of gastrointestinal function, influencing gastric motility and the overall digestive response.

5 Must Know Facts For Your Next Test

1. Gastrin is released in response to food entering the stomach, particularly proteins, which trigger its secretion.
2. The main function of gastrin is to stimulate parietal cells to produce more hydrochloric acid (HCl), creating an acidic environment for optimal enzyme activity.
3. High levels of gastrin can lead to increased gastric acid secretion, which may contribute to conditions like peptic ulcers if not properly regulated.
4. Gastrin also promotes gastric motility, enhancing the movement of food through the stomach and into the small intestine.
5. The release of gastrin is regulated through feedback mechanisms involving other hormones and the pH levels in the stomach.

Review Questions

• How does gastrin influence gastric acid secretion and overall digestive processes?
  • Gastrin significantly influences gastric acid secretion by stimulating parietal cells in the stomach to produce more hydrochloric acid. This increase in acidity aids in breaking down food and activating digestive enzymes. The presence of food, especially protein, prompts gastrin release, thus enhancing overall digestive processes and ensuring efficient digestion.
• Discuss the interplay between gastrin and other hormones in regulating gastrointestinal function.
  • Gastrin interacts with other hormones like cholecystokinin (CCK) and secretin to regulate gastrointestinal function effectively. While gastrin stimulates gastric acid production, CCK promotes enzyme release from the pancreas and bile secretion from the gallbladder, aiding digestion in the small intestine. This hormonal interplay ensures a coordinated response to food intake, optimizing digestion and nutrient absorption.
• Evaluate the implications of abnormal gastrin levels on digestive health and potential disease conditions.
  • Abnormal levels of gastrin can lead to several digestive health issues. Elevated gastrin levels often result in excessive gastric acid production, which may contribute to peptic ulcers or gastroesophageal reflux disease (GERD). Conversely, low levels of gastrin can impair digestion due to insufficient acid production. Understanding these implications helps in diagnosing and treating gastrointestinal disorders effectively.

Related terms

G cells: Specialized cells located in the gastric mucosa that secrete gastrin in response to food intake.

Hydrochloric acid (HCl): A strong acid produced by parietal cells in the stomach that aids in digestion and is stimulated by gastrin.

Cholecystokinin (CCK): A hormone released by the small intestine that stimulates the release of digestive enzymes from the pancreas and bile from the gallbladder, working alongside gastrin.