Disease relevance of Sstr1

• The gene encoding somatostatin receptor 1 is expressed in pancreatic beta-cells and insulinoma RIN 1046-38 cells [1].
• In transfected GH12C1 cells, both SSTR1 and SSTR2 coupled to inhibition of Ca2+ influx and hyperpolarization of membrane potential via a pertussis toxin (PTx)-sensitive mechanism [2].
• CONCLUSIONS: The authors showed an impressive antitumor effect of SSR (subtype 2)-transfected colon carcinoma cells with PRRT in a rat liver metastasis model [3].
• In the present study, we have investigated the role of estrogens in the regulation of somatostatin receptor subtype (sst) expression in 7315b PRL-secreting rat pituitary tumor cells in vitro and in vivo. sst were undetectable in freshly dispersed cells of the transplantable 7315b tumor [4].
• Moreover, the data demonstrate that somatostatin receptor agonists may have therapeutic potential for some prolactinomas [5].

Psychiatry related information on Sstr1

• Food deprivation enhances somatostatin and somatostatin receptor subtype expression in rat colon [6].

High impact information on Sstr1

• It was found that the pituitary and pancreas have predominantly one type of somatostatin receptor whereas the brain has both, and that different regions of the brain have various proportions of the two types [7].
• Somatostatin suppresses endothelin-1-induced rat hepatic stellate cell contraction via somatostatin receptor subtype 1 [8].
• Distribution of somatostatin receptor messenger RNAs in the rat gastrointestinal tract [9].
• Somatostatin receptor subtype 2 mediates somatostatin inhibition of ion secretion in rat distal colon [10].
• RESULTS: Polymerase chain reaction performed with templates from an ECL cell complementary DNA library and primers specific to each of the five known somatostatin receptor subtypes showed that the somatostatin receptor type 2 was significantly enriched in ECL complementary DNA [11].

Chemical compound and disease context of Sstr1

• Somatostatin receptor gene therapy combined with targeted therapy with radiolabeled octreotide: a new treatment for liver metastases [3].
• 17-beta-estradiol-dependent regulation of somatostatin receptor subtype expression in the 7315b prolactin secreting rat pituitary tumor in vitro and in vivo [4].
• The effects of MK 678 were reversible and blocked by pertussis toxin pretreatment, suggesting that SSTR2 couples to the L-type Ca2+ channels via G proteins [12].
• The somatostatin receptor subtype sst2 was visualized by immunostaining on cultivated rat astrocytes and C6 rat glioma cells [13].
• BACKGROUND: The somatostatin analog, angiopeptin, inhibits intimal hyperplasia formation; although the specific somatostatin receptor (SSTR) subtypes transducing this effect are unknown [14].

Biological context of Sstr1

• Although pituitary GH output is suppressed in the fasted rat, we report herein that pituitary GHRH receptor (GHRH-R) and GH secretagogue receptor (GHS-R) mRNA levels are increased, while pituitary expression of the somatostatin receptor subtype 2 (sst2) and 5 (sst5) is decreased, as determined by real-time reverse transcription (RT)-PCR [15].
• The growth response required SSTR2, G alpha proteins, and an intact signal transduction pathway [16].
• The POU domain transcription factor Tst-1 activates somatostatin receptor 1 gene expression in pancreatic beta -cells [1].
• Agonist-induced desensitization, internalization, and phosphorylation of the sst2A somatostatin receptor [17].
• Kinetics of somatostatin receptor migration in isolated pancreatic islets [18].

Anatomical context of Sstr1

• NPY neurons express somatostatin receptor subtype 1 in the arcuate nucleus [19].
• This study investigated the somatostatin receptor subtype on ECL cells [11].
• METHODS: Somatostatin receptors were measured in the gastric mucosa of healthy rats and of rats with cryoulcers and acetic acid-induced ulcers, using somatostatin receptor autoradiography with 125I-[Tyr3]-octreotide or 125I-[Leu8, D-Trp22, Tyr25]-somatostatin-28 as radioligands [20].
• In sst2 delta cells, SSTR2 functionally interacted with both a chimeric yeast/mammalian G alpha protein and the yeast G alpha protein, Gpa1p; to promote growth [16].
• Immunohistochemical and cytochemical localization of the somatostatin receptor subtype sst1 in the somatostatinergic parvocellular neuronal system of the rat hypothalamus [21].

Associations of Sstr1 with chemical compounds

• Somatostatin released from capsaicin-sensitive afferents exerts systemic anti-nociceptive actions, presumably via somatostatin receptor subtype 4 (sst4) [22].
• In the second experiment, we iontophoretically applied the somatostatin receptor agonist sandostatin on PnC neurons and extracellularly recorded the activity of PnC neurons [23].
• 8. The soluble somatostatin receptor is a glycoprotein which can be specifically bound to the wheat germ agglutinin lectin and eluted by triacetyl-chitotriose [24].
• Functional coupling of SSTR4, a major hippocampal somatostatin receptor, to adenylate cyclase inhibition, arachidonate release and activation of the mitogen-activated protein kinase cascade [25].
• Characterization of 17-beta-estradiol-dependent and -independent somatostatin receptor subtypes in rat anterior pituitary [26].

Physical interactions of Sstr1

• Analogues of somatostatin bind selectively to brain somatostatin receptor subtypes [27].
• A comparison with immunohistochemical staining using antisera against somatostatin receptor sequences revealed that the marked binding in laminae I-III coincided with the presence of somatostatin receptor-like immunoreactivity for the receptor subtypes 1, 2 and 3 [28].
• Involvement of a Pit-1 binding site in the regulation of the rat somatostatin receptor 1 gene expression [29].

Enzymatic interactions of Sstr1

• After somatostatin 28 treatment of membranes, purified somatostatin receptor preparations exhibited an elevated tyrosine phosphatase activity that dephosphorylated phosphorylated epidermal growth factor receptor and poly(Glu,Tyr) [30].

Regulatory relationships of Sstr1

• Inhibitory role of the somatostatin receptor SST2 on the intracrine-regulated cell proliferation induced by the 210-amino acid fibroblast growth factor-2 isoform: implication of JAK2 [31].
• This in vitro study investigated the anti-secretory potential of a group of novel, non-peptide, somatostatin-receptor agonists that selectively activate specific SSTR subtypes to assess their potential for oral administration [32].
• Thus, SSTR4 appears to stimulate MAP kinase and cPLA2 in a Gi-dependent, and through a wortmannin-sensitive pathway [33].
• The five different rat somatostatin receptor subtypes (SSTR1-SSTR5) were coexpressed with a subunit of G-protein gated inwardly rectifying potassium channel (GIRK1) in Xenopus oocytes [34].
• Agonist-induced endocytosis of somatostatin receptors determines subsequent cellular responsiveness to peptide agonist and influences somatostatin receptor scintigraphy, a technique to image various tumours [35].

Other interactions of Sstr1

• Characterization of 5'-flanking region of rat somatostatin receptor sst2 gene: transcriptional regulatory elements and activation by Pitx1 and estrogen [36].
• A differential expression of somatostatin receptor SSTR2, not known to be a cocaine-responsive gene, as well as the clock gene Per2, were found by microarrays and confirmed by RNase protection assay [37].
• The SRIF2 receptor is sensitive to the CGP-23996-like compounds and can be selectively labeled by 125I-CGP-23996 in the presence of high concentrations of the hexapeptides or GTP gamma S because, unlike the SRIF1 receptor, the SRIF2 receptor is insensitive to these agents [27].
• Growth hormone-releasing hormone-synthesizing neurons are a subpopulation of somatostatin receptor-labelled cells in the rat arcuate nucleus: a combined in situ hybridization and receptor light-microscopic radioautographic study [38].
• On the mechanism of cytosolic phospholipase A2 activation in CHO cells carrying somatostatin receptor: wortmannin-sensitive pathway to activate mitogen-activated protein kinase [33].

Analytical, diagnostic and therapeutic context of Sstr1

• Differential regulation of somatostatin receptor types 1-5 in rat aorta after angioplasty [39].
• Isoelectric focusing of soluble receptors revealed that the somatostatin receptor is an acidic protein with pI 4 [24].
• Molecular cloning and expression of a pituitary somatostatin receptor with preferential affinity for somatostatin-28 [40].
• The expression of five somatostatin receptor subtypes, rsstr1-5, was examined in rat pituitary by in situ hybridization histochemistry [41].
• Receptor-targeted scintigraphy and radionuclide therapy with radiolabeled somatostatin analogs are successfully applied for somatostatin receptor-positive tumors [42].

References