Somatostatin (sst) Receptors

Somatostatin (somatotropin release inhibiting factor, SRIF) is an endogenous cyclic polypeptide with two biologically active forms. It is an abundant neuropeptide and has a wide range of physiological effects on neurotransmission, secretion and cell proliferation.

Products
Background
Literature
Gene Data

Agonists

Cat No Product Name / Activity
2454 CH 275
Potent and selective sst1 receptor agonist
2444 (1R,1'S,3'R/1R,1'R,3'S)-L-054,264
Potent and selective sst2 agonist
1979 L-803,087 trifluoroacetate
Potent and selective sst4 agonist
1980 L-817,818
Potent and selective sst5 agonist
2440 NNC 26-9100
Selective sst4 agonist
1818 Octreotide
sst2, sst3 and sst5 agonist
3139 RC 160
sst analog
1836 Seglitide
sst2 and sst5 agonist
1157 Somatostatin
Influences growth hormone release
1165 Somatostatin 1-28
sst receptor agonist
5080 TC-G 1003
High affinity somatostatin sst2 receptor agonist
4639 TT 232
sst1/sst4 somatostatin receptor agonist

Antagonists

Cat No Product Name / Activity
3493 Cyclosomatostatin
Non-selective sst receptor antagonist
1843 CYN 154806
Selective sst2 antagonist

Other

Cat No Product Name / Activity
1844 BIM 23056
sst receptor ligand
3374 Cortistatin 14
Endogenous neuropeptide; binds sst1 - sst5 and ghrelin receptor

Somatostatin (somatotropin release inhibiting factor, SRIF) is an endogenous cyclic polypeptide with two biologically active forms. It is an abundant neuropeptide and has a wide range of physiological effects on neurotransmission, secretion and cell proliferation. The somatostatin receptor family consists of five subtypes, sst1-5, each differentially distributed throughout the central nervous system and periphery. Endogenous somatostatin receptor ligands include somatostatin-14 and somatostatin-28.

Somatostatin receptors have diverse biological functions due to their varied distribution and the fact that they couple to different second messengers - namely adenylyl cyclase, PLC, K+ channels and Ca2+ channels, amongst others.

Somatostatin receptors in the hypothalamus are involved in the regulation of growth hormone secretion. Other hormones regulated by somatostatin receptors include thyrotropin and prolactin. Somatostatin has antiproliferative effects via stimulation of protein tyrosine phosphatase activity and of the MAPK signaling cascade, with subsequent induction of G1 cell cycle arrest (sst1, sst4, sst5) and promotion of apoptosis (sst2, sst3). It also exhibits antiangiogenic activity via activation of sst3. Somatostatin regulates neuronal activity by regulating AMPA/kainate-mediated responses to glutamate. Different sst subtypes have opposing effects in this system.

Somatostatin receptors also play a role in blood glucose homeostasis; sst5 receptors in the pancreatic β-cells stimulate insulin secretion, whilst sst2 receptors are involved in glucagon secretion from α-cells. In addition, sst2 receptors inhibit gastric acid secretion and peristalsis in the jejunum. Somatostatin suppresses the release of numerous gastrointestinal hormones, including gastrin, cholecystokinin, secretin and VIP, and consequently plays an integral role in gastrointestinal endocrinology.

External sources of pharmacological information for Somatostatin (sst) Receptors :

Literature for Somatostatin (sst) Receptors

GPCR

GPCR Product Listing

A collection of over 450 products for G protein-coupled receptors, the listing includes research tools for the study of:

  • Rhodopsin-like Receptors
  • Secretin-like Receptors
  • Glutamate Receptors
  • Frizzled Receptors
  • GPCR Signaling
Peptide Hormone Receptors

Peptide Hormone Receptors Product Listing

A collection of over 200 products for peptide hormone receptors, the listing includes research tools for the study of:

  • Anterior Pituitary Regulation
  • Blood Pressure Regulation
  • Feeding and Appetite Regulation
  • Glucose Regulation
  • Peptide Hormone Processing
Cardiovascular

Cardiovascular Poster

Cardiovascular disease remains one of the major causes of morbidity and mortality in the Western world and therefore this therapeutic area continues to be of great interest to researchers. This poster highlights the key GPCRs regulating vascular reactivity.

Somatostatin Receptor Gene Data

Gene Species Gene Symbol Gene Accession No. Protein Accession No.
sst1 Human SSTR1 NM_001049 P30872
Mouse Sstr1 NM_009216 P30873
Rat Sstr1 NM_012719 P28646
sst2 Human SSTR2 NM_001050 P30874
Mouse Sstr2 NM_001042606 P30875
Rat Sstr2 NM_019348 P30680
sst3 Human SSTR3 NM_001051 P32745
Mouse Sstr3 NM_009218 P30935
Rat Sstr3 NM_133522 P30936
sst4 Human SSTR4 NM_001052 P31391
Mouse Sstr4 NM_009219 P49660
Rat Sstr4 NM_031547 P08485
sst5 Human SSTR5 NM_001053 P35346
Mouse Sstr5 NM_011425 O08858
Rat Sstr5 NM_012882 P30938

Somatostatin Receptor Data

Receptor Subtype sst1 sst2 sst3 sst4 sst5
Transduction Mechanism Gi Gi Gi Gi Gi
Primary Distribution Stomach, jejunum, pituitary Cerebrum, kidney, pituitary Cerebrum, pituitary, pancreas Cortex, hypothalamus, lung Pituitary, hypothalamus, small intestine
Key Compounds Ki/IC50 (nM)
Agonists BIM 23052 (2842)
L-803,087 (1979)
L-817,818 (1980)
Octreotide (1818)
RC 160 (3139)
Seglitide (1836)
Somatostatin (1157)
Somatostatin 1-28 (1165)
31.3
199
3.3
> 1000
> 1000
> 1000
1.1
2.2
13.5
4720
52
2.1
5.4
1.5
1.3
4.1 -
-
1280
64
4.4
30.9
27
1.6
6.1
141
82
0.7
> 1000
45
127
0.53
1.1
7.3
3880
0.4
5.6
0.7
2
0.9
0.07
Antagonists BIM 23056 (1844)
CYN 154806 (1843)
142
5.41*
> 1000
8.85*
10.8
6.07*
16.6
5.76*
5.7
6.48*

* pIC50 values

References

Moller et al (2003) Somatostatin Receptors. Biochem.Biophys.Acta. 1616 1. Alexander et al (2004) Guide to receptors and channels. Br.J.Pharmacol. 141 Suppl.1. Patel and Srikant (1995) Subtype selectivity of peptide analogues for all five cloned human somatostatin receptors (hsstr 1-5). Endocrinology 135 2814. Fenuik et al (2000) Selective somatostatin sst2 receptor blockade with the novel cyclic octapeptide, CYN-154806. Neuropharmacology 39 1443. Rohrer and Schaeffer (2000) Identification and characterization of subtype selective somatostatin receptor agonists. J.Physiol. 94 211.