Somatostatin

approved

Also known as: Growth hormone-inhibiting hormone, SST-14

**Mechanism of Action** Somatostatin (SST-14) is an endogenous cyclic tetradecapeptide that exerts its effects through binding to five G-protein-coupled somatostatin receptors (SSTR1–5). Activation of these receptors inhibits adenylyl cyclase, reduces intracellular cAMP, and modulates ion channels (e.g., potassium and calcium channels), leading to suppression of hormone secretion. Key targets include growth hormone (GH) from the anterior pituitary, insulin and glucagon from pancreatic islets, and gastric acid, pepsin, and gastrin from the gastrointestinal tract. This broad inhibitory profile underlies its regulatory role in endocrine and exocrine systems. **Key Research Findings** With over 34,980 PubMed references, somatostatin is extensively studied. Early research established its role as a GH-inhibiting factor, counteracting growth hormone-releasing hormone (GHRH). Subsequent studies demonstrated its paracrine and autocrine functions in the hypothalamus, pancreas, and gut. Synthetic analogs (e.g., octreotide, lanreotide) with prolonged half-lives have been developed, showing efficacy in reducing GH and IGF-1 levels in acromegaly and controlling symptoms of neuroendocrine tumors (e.g., carcinoid syndrome). Research also highlights its anti-proliferative effects on tumor cells via SSTR2-mediated signaling. **Clinical Relevance** Somatostatin and its analogs are approved for treating acromegaly, neuroendocrine tumors (e.g., gastroenteropancreatic tumors), and conditions like Cushing’s disease (via pasireotide). They are also used to manage acute variceal bleeding and secretory diarrhea. Side effects include gallstones, hyperglycemia, and gastrointestinal disturbances. Long-acting formulations improve patient compliance. Ongoing research explores SSTR-targeted imaging (e.g., ⁶⁸Ga-DOTATATE PET) and radionuclide therapy (e.g., ¹⁷⁷Lu-DOTATATE) for advanced neuroendocrine cancers. For research purposes only — not medical advice.

Key data

Category
Growth Hormone Peptides
Molecular weight
1637.9 g/mol
Molecular formula
C76H104N18O19S2
CAS number
38916-34-6
Half-life
1-3 minutes
Administration
intravenous
Research status
approved
References
35,107
Tags
endogenous, inhibitory

Research & studies

Somatostatin modulation of initial fusion pores in Ca(2+)-triggered exocytosis from mouse chromaffin cells
The Journal of physiology · 2025 · PubMed
Neuropeptidergic transmission shapes emergent properties of prefrontal cortical circuits underlying learning
bioRxiv : the preprint server for biology · 2025 · PubMed

Somatostatin release and receptor antagonism revealed time-dependent regulation of outcome-specific associative learning.; Somatostatin transmission enables configural representations incorporating salient aversive outcomes in prefrontal cortical neurons.; Somatostatin signaling drives a threat-induced shift in population-level network activity in vivo.; Reduced somatostatin neuropeptidergic transmission may impair top-down control of affective behaviors in mental health disorders.

Pharmacologic inhibition of somatostatin receptor 2 to restore glucagon counterregulation in diabetes
Frontiers in pharmacology · 2024 · PubMed
Somatostatin and Somatostatin Receptors: From Signaling to Clinical Applications in Neuroendocrine Neoplasms
Biomedicines · 2021 · PubMed
The somatostatin-secreting pancreatic δ-cell in health and disease
Nature reviews. Endocrinology · 2018 · PubMed

δ-cells have complex morphology and interact with many islet cells despite low numbers.; Glucose elevation closes ATP-sensitive potassium channels in δ-cells, triggering somatostatin secretion.; Somatostatin acts locally via inhibitory G protein-coupled receptors to suppress insulin and glucagon secretion.; Perturbed somatostatin secretion in diabetes may explain defective glucagon responses to hypoglycemia.

Somatostatin and dopamine receptor regulation of pituitary somatotroph adenomas
Pituitary · 2017 · PubMed

Somatostatin and dopamine receptors suppress GH secretion by inhibiting adenylate cyclase and reducing intracellular calcium.; Somatostatin receptor subtype 2 is the main mediator of GH suppression, with SST5 playing a lesser role.; Mutations in SST5 are associated with GH levels, somatotroph tumor behavior, and response to somatostatin receptor ligands.; Receptor complexes may exhibit functions distinct from monomers, potentially influencing treatment efficacy.

Somatostatin and Somatostatin-Containing Neurons in Shaping Neuronal Activity and Plasticity
Frontiers in neural circuits · 2016 · PubMed

Somatostatin acts as a neurotransmitter or neuromodulator, fine-tuning neuronal activity and influencing synaptic plasticity and memory formation.; Multiple subpopulations of SOM-containing interneurons have distinct anatomical and physiological features that control cortical excitatory neuron output.; Somatostatin itself modulates excitability and neuronal responses via pre- and postsynaptic actions.; The somatostatinergic system is a significant player in shaping nervous system activity and plasticity.

Pancreatic polypeptide inhibits somatostatin secretion
FEBS letters · 2014 · PubMed

NPY4R is expressed in all somatostatin-containing cells of pancreatic islets, duodenum, hippocampus, and hypothalamus.; PP agonism of NPY4R decreases somatostatin secretion from human islets.; Activation of NPY4R by PP reduces somatostatin secretion in mouse embryonic hippocampal cells.; Central injection of PP in mice increases c-Fos immunoreactivity in hippocampal somatostatin-containing cells.

Frequently asked questions

What is Somatostatin?

**Mechanism of Action** Somatostatin (SST-14) is an endogenous cyclic tetradecapeptide that exerts its effects through binding to five G-protein-coupled somatostatin receptors (SSTR1–5). Activation of these receptors inhibits adenylyl cyclase, reduces intracellular cAMP, and modulates ion channels (e.g., potassium and

How does Somatostatin work?

Endogenous cyclic peptide that inhibits GH, insulin, glucagon, and gastric secretion via SSTR1-5 receptors.

What is the research status of Somatostatin?

Somatostatin is currently classified as approved, with 35,107 research references on record. This is for research purposes only and is not medical advice.

What is the half-life of Somatostatin?

The reported half-life of Somatostatin is 1-3 minutes.

What is the molecular weight of Somatostatin?

Somatostatin has a molecular weight of approximately 1637.9 g/mol (formula C76H104N18O19S2).

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