Question

Which of the following belongs to local hormones?
A. Gastrin
B. Atrial natriuretic factor
C. Prostaglandins
D. All of the above

Answer 1

Hint: These hormones are produced by nerve and gland cells that do not circulate within the blood.

Complete answer:
Local hormones are a large group of signaling molecules that include eicosanoids, prostaglandins, gastrin, secretin, and so on. The main characteristics of these hormones are they get activated and inactivated quickly and mainly released at the time of physical work and exercise. Local hormones mainly regulate the smooth and vascular muscle dilation. The strength of the response is depending on the concentration of receptors of the target cells and the number of ligands or hormones.
> Gastrin: Gastrin is a polypeptide hormone that is secreted by the mucous lining of the stomach. It regulates the gastric functions together with gastric acid secretion.
> Prostaglandins: These hormones are derived from fatty acids and come under eicosanoids. > They are synthesized in most tissues of the body. These types of local hormones excite pain receptors and increase the inflammatory response. It performs various functions such as regulation of blood pressure, inflammation, induction of labor, and the formation of blood clots.
> Atrial natriuretic factor: It is an exception that acts as both local hormone and endocrine that is produced locally by immune cells. It causes vasodilation and hence decreases the blood pressure. It also acts on the kidney to increase sodium and water excretion.

So, the correct answer is ‘all of the above’.

Note:
- Gastrin family is the peptide hormones that include gastrin and cholecystokinin. They both serve as regulators of various digestive processes.
- A hormone-receptor complex stimulates a chain of definite chemical responses within the target cells to complete hormonal action.