What do chief cells secrete?

Chief cells are specialized cells located in the gastric glands of the stomach lining, and their primary function is to produce and secrete pepsinogen, which is an inactive enzyme. When pepsinogen is released into the acidic environment of the stomach, it is converted into pepsin, an active enzyme that begins the digestion of proteins. This process is essential for effective digestion, enabling the breakdown of large protein molecules into smaller peptides.

Understanding the role of chief cells in digestion highlights the specific and critical nature of their secretions. Pepsinogen is secreted in its inactive form to prevent the enzyme from digesting the cell's own proteins and harming the tissue before it is needed in the digestive process. This mechanism illustrates the importance of regulated enzyme activation in maintaining digestive health.

In the context of gastric secretion, it is also noteworthy that other cells in the gastric lining, such as parietal cells, secrete intrinsic factor and hydrochloric acid, and mucus-secreting cells provide a protective mucosal barrier. However, the specific role of chief cells is tied directly to the secretion of pepsinogen, which is central to protein digestion in the stomach.