Question

Pepsinogen is secreted by
a. Chief cells
b. Oxyntic cells
c. Mast cells
d. Parietal cells

Answer 1

Hint: Pepsinogen is one of the influential and profuse protein digestive enzymes found in the human body. This enzyme is generally as in the form of proenzyme and then converted into the active enzyme. It is used to digest the food material which is usually taken by us. On brief research, one can conclude that it is one of the most imperative proteolytic enzymes of abomasal fluid.

Complete answer:
- There is the presence of a cell called a gastric chief cell in the stomach that releases Pepsinogen and chymosin. This cell is also called a zymogenic cell or peptic cell.
- When the enzyme called Pepsinogen is activated into the digestive enzyme, it usually is inactive. However, on the other hand, it becomes active in the form of pepsin when it originates in interaction with acid, which is formed by gastric parietal cells.
- Pepsinogen is not secreted by parietal cells, intestinal glands, or gastric glands.
- The oxyntic cells of parietal cells are made to produce the gastric acid (called as the hydrochloric acid) in retort to histamine, acetylcholine (called as M3 receptors), and gastrin (called as gastrin receptors).
- These cells comprise a widespread secretory network (which is called canaliculi) from which the HCl is concealed by active transportation into the stomach.
- The mast cells are involved in generating and releasing numerous multi potent fragments, and growth factors such as proteases, prostanoids, histamine, leukotrienes, cytokines, heparin, and many chemokines.

Hence, the correct answer is option (A).

Note: As we now, a single polypeptide chain is present in Pepsinogens consisting of the molecular weight of approximately 42,000 Da. Generally, Pepsinogens are manufactured and concealed principally by the chief gastrointestinal cells of the human stomach. And then they will get transformed into the proteolytic enzyme pepsin. This transformation is critical for digestive procedures in the stomach.