Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P61278 (somatostatin)
 22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Capillary electrophoresis (CE) and micellar electrokinetic chromatography (MEKC) methods, utilizing uncoated silica capillary and triethyl ammonium phosphate or sodium borate buffers in the pH range of 2.25-11.0, containing sodium dodecyl sulfate (SDS) (0-100 mM) for analysis of somatostatin-analog peptides were developed. The method presented here was compared with the reversed-phase high performance liquid chromatographic (RP-HPLC) and CE methods developed for analysis of peptides. The peptides investigated in this work can be separated by CE on the basis of their electrophoretic mobility in aqueous buffer of low pH value (pH 2.25) or by MEKC on the basis of their hydrophobicity in SDS containing buffer of high pH value (pH 11.0). Optimal MEKC separation of the investigated peptides has been achieved at pH 11.0 in an Na-borate buffer containing 100 mM SDS. CE at pH 2.25 proved insensitive to the hydrophobicity of the peptides investigated. By contrast, results obtained with MEKC at pH 11.0 proved to be anologous to those obtained by RP-HPLC, with highly hydrophobic peptides-migrating slower than peptides without hydrophobic moieties.
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PMID:Comparative analysis of somatostatin analog peptides by capillary electrophoresis and micellar elektrokinetic chromatography. 873 39

The signal transduction pathways regulated by somatostatin receptor subtype 1 (sst1) have been difficult to define because of the variability observed when this receptor is expressed in different cell types by transfection and because pharmacological approaches are inadequate to distinguish sst1 receptor subtypes. To study the sst1 receptor in its endogenous environment, we developed a polyclonal antibody to a 15-amino acid peptide corresponding to a unique sequence in the receptor carboxyl terminus. The peptide antibody routinely precipitated 70% of the soluble [125I-Tyr11]somatostatin/receptor complex prepared from Chinese hamster ovary-K1 cells expressing the sst1 receptor but precipitated < 1% of the complex from cells expressing other sst receptor subtypes. Photoaffinity-labeled sst1 receptor was also specially immunoprecipitated and migrated as a broad 60-kDa band on sodium dodecyl sulfate polyacrylamide gels. The observation that sst receptors from GH4C1 pituitary cells were immunoprecipitated by the antibody and that receptors from AR4-2J pancreatic acinar cells were not indicated that only the former expressed sst1 receptor protein. Because reverse transcription-polymerase chain reaction showed that GH4C1 cells contained both sst1 and sst2 receptor mRNA, immunoprecipitation permitted the sst1 receptor to be separated from the other receptors present. Two observations showed that G proteins were coprecipitated with sst1 receptors from GH4C1 cells. First, pertussis toxin pretreatment markedly decreased hormone binding in the immunoprecipitate. Second, the addition of 20 microM guanosine-5'-(gamma-thio)triphosphate to the immunoprecipitated [125I-Tyr11]somatostatin/receptor complex stimulated the rate of dissociation of bound ligand by 10-fold. Interestingly, however, the dissociation rate of approximately 30% of the ligand/receptor complex was unaffected by guanosine-5'-(gamma-thio)triphosphate. In summary, we have developed an sst1 receptor-specific antibody and used it to show that sst1 receptors endogenously expressed in GH4C1 pituitary cells couple primarily to pertussis toxin-sensitive G proteins. Furthermore, these receptors exist in two distinct high affinity states distinguished by their GTP sensitivity.
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PMID:Development and use of a receptor antibody to characterize the interaction between somatostatin receptor subtype 1 and G proteins. 884 99

Immunoreactivity specific to keratan sulfate (KS), heparan sulfate (HS), and chondroitin sulfate (CS) in the nasal region of chick embryos on embryonic day (ED) 3.5-7, was investigated with six antibodies and three glycosidases. Immunoreactivity specific to HS, KS, and CS, and their localized distribution was seen in the olfactory epithelium, olfactory nerve, and cells located along the bundles of the olfactory nerve on ED 3.5-7. The immunoreactivity to HS was seen in the cells and their neurites located in the olfactory nerve bundles and in cells in the ventral forebrain on ED 3.5-5. The cells, i.e., gonadotropin-releasing hormone (GnRH)-or somatostatin-containing cells, are reported to originate in the olfactory epithelium, migrate along the olfactory nerve, and then invade the forebrain in chick embryos. These findings taken together, indicated that a subset of cells migrating along the nerve to the forebrain contained HS. Limited immunoreactivity to KS in the olfactory epithelium and in the underlying mesenchyme, but not in the olfactory nerve, ruled out the involvement of this glycosaminoglycan (GAG) in the migration of cells along the olfactory nerve. The immunoreactivity to CS and to its derivatives suggested the presence of CS in proteoglycan form in the olfactory structures and migrating cells.
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PMID:Glycosaminoglycans in the olfactory epithelium and nerve of chick embryos: an immunocytochemical study. 892 23

We demonstrated previously that pancreatic secretion of individual enzymes is specifically regulated (1). In the present study, we investigated and defined contributing roles of cholinergic and cholecystokinin tones to the specific regulation of rat pancreatic secretion of digestive enzymes. Animals were provided with pancreatic, biliary, duodenal, and jugular vein cannulas allowing separate drainage of bile and pure pancreatic juice, as well as intravenous infusions of MK329 or atropine sulfate along with SMS 201-995 (SMS). Rats kept in restraint cages were divided into four groups. The first rat group was infused with 5 micrograms kg-1 h-1 SMS alone; the second group was infused with a mixture of SMS and MK329 (5 micrograms kg-1 h-1:0.5 mg kg-1 h-1); the third group received a mixture of SMS and atropine (5 micrograms kg-1 h-1); and rats in the fourth group were administrated a mixture of SMS, MK329, and atropine (5 micrograms kg-1 h-1:0.5 mg kg-1:100 micrograms kg-1 h-1). Food, but not water, was denied rats 10 h before the experiment and throughout the 6-h experimental period. During the experiment, pancreatic juice was continuously collected every 15 min from each rat, and a 15-microliter aliquot of the pancreatic juice sample was removed for total protein, amylase, lipase, trypsinogen, chymotrypsinogen, and proelastase assays. Pancreatic juice previously collected from a donor rat was mixed with the fresh bile and the mixture was recirculated into the duodenum. The secretory patterns over the 6-h experimental period showed that during the first hour of drug infusion, MK329 alone did not alter the SMS-induced inhibitory process of total protein and amylase, trypsinogen, and proelastase secretion, and there was no marked change in total protein and enzyme outputs. Adding atropine to SMS did not alter the secretory pattern during the first hour of drug infusion, but a significantly greater decrease in protein and enzymes outputs occurred. Correlations between paired enzyme outputs greatly increased with SMS alone, but some changed when either MK329 or atropine was infused along with SMS. When all drugs were infused together, enzyme outputs became strongly correlated. These results suggest that under fasting conditions, somatostatin and atropine can neutralize basal pancreatic enzyme outputs, leading to a constitutive type of secretion characterized by parallel secretion of the digestive enzymes. Furthermore, it is proposed that under basal secretion conditions, acetylcholine and cholecystokinin reaching the pancreatic acinar cells may act to dissociate pancreatic secretion of individual digestive enzymes originating from heterogeneous secretory granules.
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PMID:Modulation of pancreatic secretion of individual digestive enzymes in octreotide (SMS 201-995)-infused rats. 898 7

Tryptase purified from rat and dog tissues has been reported, although the characteristics of these enzymes are different from human tryptase. For pathophysiological studies of human tryptase, studies on species that have a similar tryptase to humans is needed. In this study, we purified monkey tryptase from cheek pouch vascular tissues using heparin affinity and gel filtration columns. The monkey tryptase, which had a molecular weight of 130 kDa by gel filtration, consisted of a tetramer of 33 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The N-terminal sequence showed high homology with tryptases from other species. The optimum pH and temperature were 7.5-9.0 and 25-40 degrees C, respectively. The enzyme was labile in high-KCl buffer, and the optimum KCl concentration was 0.1 M. The enzyme activity was completely inhibited by diisopropyl phosphorofluoridate and leupeptin but not by soybean trypsin inhibitor and alpha-antitrypsin. The enzyme hydrolyzed vasoactive intestinal peptide but did not affect angiotensin I, somatostatin and bradykinin. In the present study, we first isolated monkey tryptase from cheek pouch vascular tissues and showed that the characteristics of monkey tryptase are very similar to those of human tryptase.
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PMID:Characteristics of monkey tryptase purified from cheek pouch vascular tissues. 1120 8

We evaluated whether the combination of triptorelin, a LHRH analog (LHRH-A), with dexamethasone and lanreotide, a somatostatin analog, can produce objective clinical responses in metastatic androgen ablation-refractory prostate cancer (stage D3) patients who have relapsed, after combined androgen blockade (LHRH-A plus antiandrogen) and antiandrogen withdrawal. Eleven stage D3 patients with diffuse bony metastases, who had progressed despite initial responses (lasting <12 months) to combined androgen blockade therapy and subsequently failed antiandrogen withdrawal, received oral dexamethasone (4 mg daily for the first month, tapered down to 2 mg after the first month and 1 mg after the second month, and continued on 1 mg thereafter) and lanreotide (30 mg im every 14 d) in combination with triptorelin (3.75 mg im every 28 d). Serum prostate-specific antigen, alkaline phosphatase, performance status, and bone pain were assessed monthly during therapy. Fasting blood glucose was measured biweekly, and serum IGF-I, T, and dehydroepiandrosterone sulfate levels were assessed at baseline, at response to the combination therapy, and at relapse from it. Ten of 11 stage D3 patients [90.9% of patients; 95% confidence interval (CI), 58.7-99.8%] had durable objective clinical responses (including > or = 50% prostate-specific antigen decline in 8 patients, 72.7%; 95% CI, 39-94%). All patients reported significant and durable improvement of bone pain (for a median duration of 13 months; 95% CI, 12-14 months; range, 6-22 months) and performance status (median duration, 19 months; 95% CI, 13-25 months; range, 7-22 months) without major treatment-related side effects. The median progression-free survival was 7 months (95% CI, 4-10 months; range, 3-17 months), and the median overall survival was 18 months (95% CI, 16-20 months; range, 7-22 months). Five of six total deaths occurred secondary to disease progression. We observed a statistically significant (P = 0.018) reduction in serum IGF-I levels at response to the combination therapy (60% reduction of baseline IGF-I levels). Dehydroepiandrosterone sulfate levels, although already significantly suppressed at baseline, had an additional significant reduction (P < 0.02) at response to therapy. T levels remained suppressed within castration levels (<3 nmol/liter, at baseline and throughout therapy, including relapse). The combination therapy of LHRH-A with dexamethasone plus somatostatin analog produces objective clinical responses and symptomatic improvement in androgen ablation (LHRH-A) refractory prostate cancer patients.
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PMID:A combination therapy of dexamethasone and somatostatin analog reintroduces objective clinical responses to LHRH analog in androgen ablation-refractory prostate cancer patients. 1173 29

Opioid receptors are expressed in cells of the immune system, and potent immunomodulatory effects of their natural and synthetic ligands have been reported. In some studies, the opiate receptor antagonist naloxone itself displayed immunomodulatory actions. We investigated effects of naloxone on leukocyte chemotaxis. Cell migration was tested in micropore filter assays using modified Boyden chambers, and receptor expression was investigated using radiolabel binding assays. Naloxone induced peripheral blood nonadherent mononuclear cell and neutrophil chemotaxis at nanomolar concentrations and deactivated their migration toward beta-endorphin, angiotensin II, somatostatin, or interleukin-8 but not toward RANTES, vasoactive intestinal peptide, or substance P. Ligand binding studies showed no alteration in the binding of interleukin-8 to neutrophils by naloxone. Cleavage of heparan sulfate from proteoglycans on the cells' surface completely inhibited chemotactic and deactivating properties of naloxone but not other attractants. Chemotactic properties were abolished by pretreating cells with heparinase, chondroitinase, sodium chlorate, and anti-syndecan-4 antibodies, indicating the involvement of syndecan-4. The extent of migration toward naloxone was diminished by pretreatment with dimethylsphingosine, a specific sphingosine kinase inhibitor. As syndecan-4 signaling in leukocyte chemotaxis involves activation of sphingosine kinase, results indicate that naloxone interacts with syndecan-4 function in cell migration and suggest a role for heparan sulfate proteoglycans as coreceptors to members of the delta-opiate receptor family.
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PMID:Heparan sulfate proteoglycans are involved in opiate receptor-mediated cell migration. 1470 51

Public health efforts and current antiobesity agents have not controlled the increasing epidemic of obesity. Investigational antiobesity agents consist of 1) central nervous system agents that affect neurotransmitters or neural ion channels, including antidepressants (bupropion), selective serotonin 2c receptor agonists, antiseizure agents (topiramate, zonisamide), some dopamine antagonists, and cannabinoid-1 receptor antagonists (rimonabant); 2) leptin/insulin/central nervous system pathway agents, including leptin analogues, leptin transport and/or leptin receptor promoters, ciliary neurotrophic factor (Axokine), neuropeptide Y and agouti-related peptide antagonists, proopiomelanocortin and cocaine and amphetamine regulated transcript promoters, alpha-melanocyte-stimulating hormone analogues, melanocortin-4 receptor agonists, and agents that affect insulin metabolism/activity, which include protein-tyrosine phosphatase-1B inhibitors, peroxisome proliferator activated receptor-gamma receptor antagonists, short-acting bromocriptine (ergoset), somatostatin agonists (octreotide), and adiponectin; 3) gastrointestinal-neural pathway agents, including those that increase cholecystokinin activity, increase glucagon-like peptide-1 activity (extendin 4, liraglutide, dipeptidyl peptidase IV inhibitors), and increase protein YY3-36 activity and those that decrease ghrelin activity, as well as amylin analogues (pramlintide); 4) agents that may increase resting metabolic rate ("selective" beta-3 stimulators/agonist, uncoupling protein homologues, and thyroid receptor agonists); and 5) other more diverse agents, including melanin concentrating hormone antagonists, phytostanol analogues, functional oils, P57, amylase inhibitors, growth hormone fragments, synthetic analogues of dehydroepiandrosterone sulfate, antagonists of adipocyte 11B-hydroxysteroid dehydrogenase type 1 activity, corticotropin-releasing hormone agonists, inhibitors of fatty acid synthesis, carboxypeptidase inhibitors, indanones/indanols, aminosterols, and other gastrointestinal lipase inhibitors (ATL962). Finally, an emerging concept is that the development of antiobesity agents must not only reduce fat mass (adiposity) but must also correct fat dysfunction (adiposopathy).
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PMID:Current and investigational antiobesity agents and obesity therapeutic treatment targets. 1534 Jan

Chronic hyperglycemia in diabetes is a major causative factor of free radical generation which further leads to many secondary diabetic complications via the damage to cellular proteins, membrane lipids, and nucleic acids. Zinc is an essential trace element in all living systems and plays a structural role in many proteins and enzymes. Somatostatin is known to have inhibitory effects on various gastrointestinal functions. Therefore, we determined somatostatin protein production and secretion levels, and biochemical and light microscopical changes following zinc supplementation in the gastrointestinal tract of streptozotocin (STZ)-diabetic rats. The animals were divided into four groups: Group I: control (untreated) animals; Group II: control animals given zinc sulfate; Group III: diabetic animals; and Group IV: diabetic animals given zinc sulfate. Zinc sulfate was given to the animals by gavage at a daily dose of 100 mg/kg body weight for 60 days. Diabetes was induced by intraperitoneal (i.p.) injection of STZ in a single dose of 65 mg/kg. For histological studies, stomach and duodenum tissues were fixed in Bouin solution and sections stained with Masson's trichrome and Periodic-Acid-Schiff. Tissue homogenates were used for protein, lipid peroxidation (LPO), glutathione (GSH), and nonenzymatic glycosylation (NEG) analyses. Zinc supplementation to the STZ-diabetic rats revealed the protective effect of zinc on these parameters. Zinc supplementation may contribute to prevent at least some complications of diabetes mellitus.
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PMID:Alterations in somatostatin cells and biochemical parameters following zinc supplementation in gastrointestinal tissue of streptozotocin-induced diabetic rats. 1746 Jul 67

The aim of this study was to investigate the effects of zinc supplementation on somatostatin and insulin peptide expressions and biochemical parameters. Six- to 6.5-month-old female Swiss albino rats weighing 150-200 g were used. The animals were divided into four groups: group I: control (intact) animals; group II: control animals given zinc sulfate; group III: streptozotocin (STZ)- induced diabetic animals; group IV: STZ-induced diabetic animals given zinc sulfate. Fasting blood glucose and glutathione levels were measured at 0, 1, 30 and 60 days. On day 60, the pancreas tissue and blood samples were taken from the animals. Zinc supplementation caused a decrease in hyperglycemia, as well as weight increase. Zinc sulfate treatment did not affect the number of somatostatin-immunoreactive cells in the pancreas. More insulin-immunoreactive cells were observed in the pancreatic islets of the diabetic+zinc sulfate group than in the diabetic group, although it was not statistically significant. The results show that zinc supplementation may prevent diabetes in experimental animals.
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PMID:The influence of zinc supplementation on the pancreas of streptozotocin-diabetic rats. 1911 23


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