Somatostatin is secreted by:
**Core Concept**
Somatostatin is a regulatory peptide involved in the inhibition of hormone secretion from the anterior pituitary gland and the pancreas. It plays a crucial role in maintaining homeostasis by modulating various physiological processes.
**Why the Correct Answer is Right**
Somatostatin is primarily secreted by the delta cells of the islets of Langerhans in the pancreas. These cells release somatostatin in response to high glucose levels, which in turn inhibits the release of insulin and glucagon. This regulatory mechanism helps to maintain blood glucose homeostasis. Additionally, somatostatin is also secreted by the D cells of the stomach, small intestine, and other parts of the gastrointestinal tract.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify a known source of somatostatin secretion. While there are other cells that may express somatostatin, these are not the primary sources of its secretion.
**Option B:** This option is incorrect because it does not accurately describe the primary source of somatostatin secretion.
**Option C:** This option is incorrect because it is a distractor that does not relate to the known sources of somatostatin secretion.
**Clinical Pearl / High-Yield Fact**
Somatostatin analogs, such as octreotide, are used clinically to treat various conditions, including acromegaly, carcinoid syndrome, and certain types of tumors. These analogs work by mimicking the inhibitory effects of somatostatin on hormone secretion and cell proliferation.
**Correct Answer:** D. D cells of the pancreas.