What is the function of gastrin produced by G cells?

The function of gastrin, produced by G cells, is to stimulate parietal cells in the stomach to increase the secretion of hydrochloric acid (HCl). Gastrin is a peptide hormone that is released in response to the presence of protein in the stomach and stretches that occur with food intake. Once released into the bloodstream, gastrin binds to specific receptors on the parietal cells, which are responsible for producing HCl. This increase in HCl secretion is crucial for maintaining an acidic environment in the stomach, which aids in the digestion of food, activates digestive enzymes, and helps control the growth of bacteria.

Additionally, gastrin also plays a role in promoting gastric motility and increases the secretion of other gastric juices, allowing for a more efficient digestive process. This physiological mechanism emphasizes the importance of gastrin in the digestive system, making its role in stimulating HCl secretion by parietal cells essential for proper digestive function.