Gastric glands are mostly exocrine glands that secrete various enzymes, mucus, hydrochloric acid and hormones. They are present beneath the gastric pits within the gastric mucosa. Chief cells or peptic cells and parietal cells or oxyntic cells are two types of cells found in gastric glands. Peptic cells release a zymogen (proenzyme) called pepsinogen, which is a precursor to pepsin. Oxyntic cells secrete HCl and intrinsic factor.
1. Overview and Key Difference
2. What are Peptic Cells
3. What are Oxyntic Cells
4. Similarities Between Peptic and Oxyntic Cells
5. Side by Side Comparison – Peptic vs Oxyntic Cells in Tabular Form
What are Peptic Cells?
Peptic cells are a type of gastric cells. They are also known as chief cells. These cells are present in the basal regions of the gastric gland. Therefore, they are found deep in the mucosal layer of the stomach lining. Peptic cells contain many large secretory vesicles filled with digestive enzymes. They mainly release a proenzyme called pepsinogen. It is a precursor to pepsin. Pepsin is the enzyme that catalyzes the digestion of proteins. Pepsin is formed in the presence of HCl. Hence, peptic cells work in conjunction with the parietal cells. In addition to pepsinogen, chief cells produce gastric lipase enzymes as well. Moreover, peptic cells secrete chymosin in ruminants.
What are Oxyntic Cells?
Oxyntic cells are another type of gastric cells. They are also known as parietal cells. They are present in the walls of the tubes of gastric glands. Oxyntic cells release hydrochloric acid in response to three stimulators: acetylcholine, gastrin and histamine. Therefore, oxyntic cells are the source of HCl in the stomach. They play a pivotal role in gastric homeostasis. Gastric HCL is the best-known component of gastric juice. HCl converts pepsinogen into pepsin. Moreover, oxyntic cells secrete the intrinsic factor. The intrinsic factor is a glycoprotein that is necessary for the absorption of vitamin B12 in the diet. Intrinsic factor is produced in response to gastrin, histamine, insulin, and vagal stimulation.
Structurally, oxyntic cells are pyramidal in shape. Their cell cytoplasm is packed with mitochondria, with abundant lysosomes and a specialized organelle called tubulovesicles. Moreover, oxyntic cells show two different structural changes as secreting state and resting state. Generally, the human stomach has one billion oxyntic cells. They are epithelial cells similar to peptic cells.
What are the Similarities Between Peptic and Oxyntic Cells?
- Peptic and oxyntic cells are two types of cells found in the gastric glands.
- They are epithelial cells.
- Peptic cells work in conjunction with the parietal cells because pepsinogen is converted into active pepsin by HCL.
What is the Difference Between Peptic and Oxyntic Cells?
Peptic cells are gastric gland cells that secrete pepsinogen and gastric lipases, while oxyntic cells are gastric gland cells that release HCL and intrinsic factor. So, this is the key difference between peptic and oxyntic cells.
Below is a summary of the difference between peptic and oxyntic cells in tabular form.
Summary – Peptic vs Oxyntic Cells
Peptic cells produce pepsinogen and gastric lipases, while oxyntic cells release HCl and intrinsic factor. Thus, this is the key difference between peptic and oxyntic cells. Both cells type work together. HCL is needed to convert pepsinogen into active pepsin. Both peptic and oxyntic cells are cells of gastric glands. They are important structural components of the digestion process.
1. Varela-Chinchilla, Carlos D. “Histology, Parietal Cells.” StatPearls [Internet]., U.S. National Library of Medicine, 30 June 2020, Available here.
2. “Chief Cell.” Wikipedia, Wikimedia Foundation, 6 Dec. 2020, Available here.
1. “Histopathology of fundic gland polyp, high magnification, annotated” By Mikael Häggström, M.D – Own work (CC0) via Commons Wikimedia
2. “Parietal cells” By Jpogi at English Wikipedia – Transferred from en.Wikipedia to Commons. (Public Domain) via Commons Wikimedia