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)

In order to study the role of cyclic AMP in the inhibition by somatostatin of glucose-induced insulin release, the effect of somatostatin on the potentiation by dibutyryl-cyclic AMP (db-cAMP) of insulin release from isolated pancreatic islets of rats was examined. Isolated islets were obtained from the rat pancreas by the collagenase method. Ten islets were incubated for periods of 30 min in Krebs-Ringer bicarbonate buffer containg albumin and glucose 2.0 mg/ml in the presence or absence of somatostatin (1 microgram/ml or 100 ng/ml) and/or db-cAMP 1 mM. Glucose-induced insulin release was reduced by somatostatin in concentrations of 1 microgram/ml. Somatostatin in a concentration of 100 ng/ml significantly abolished the potentiation by db-cAMP of insulin release (p less than 0;01), in spite of exerting no inhibition of glucose-induced insulin release. However, in the presence of theophylline 5 mM, somatostatin 100 ng/ml did not show that inhibitory effect on the potentiated insulin release.
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PMID:Insulin release from collagenase-isolated islets of rat pancreas in the presence of cyclic AMP and somatostatin. 20 May 35

The acute suppressive effects of L-dopa and somatostatin (growth hormone release inhibiting hormone) on the elevated plasma GH concentrations of seven patients with acromegaly were compared. In addition the effects of the two agents on fasting concentrations of plasma glucose, insulin, glucagon and prolactin were studied. In six of the seven patients hourly samples for GH assay were taken from 08.00 to 20.00 hours on a control day. Synthetic cyclic somatostatin (100 mug) was infused intravenously in an albumin/saline solution over 75 min with a Harvard constant infusion pump. Levodopa 500 mg was given orally. Somatostatin infusion produced a reduction in plasma GH concentrations in six of seven patients (mean reduction 55%). L-Dopa produced a reduction in plasma GH concentrations in the same six patients (mean reduction 52%). The minimum GH concentrations achieved in the two tests were comparable and did not differ significantly from the minimum GH concentrations recorded during the 12 h control study. Mean plasma insulin and glucagon concentrations were also significantly reduced during the somatostatin infusion (P less than 0-025; P less than 0-05 respectively). Plasma glucose concentrations did not change. L-Dopa did not alter mean plasma glucose, insulin or glucagon values. Somatostatin did not alter prolactin values but L-Dopa suppressed basal values to less than 2 ng/ml in five patients. This study shows that the plasma GH change after the administration of L-dopa and somatostatin in acromegaly is comparable and confirms the pancreatic effects of somatostatin.
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PMID:A comparison of the effect of levodopa and somatostatin on the plasma levels of growth hormone, insulin, glucagon and prolactin in acromegaly. 126 63

Intravenous administration of an alpha-adrenoceptor agonist, UK-14,304, a histamine H3 receptor agonist, R(-)-alpha-methyl-histamine (alpha-MeHA) or SMS 201-995 (a synthetic octapeptide analogue of somatostatin), blocked plasma protein (125I-albumin) extravasation within rat and/or guinea pig dura mater following unilateral electrical trigeminal ganglion stimulation or capsaicin administration. The extravasation caused by the administration of the neuropeptide mediator, substance P, was not inhibited by any of the three compounds. Blockade by UK-14,304 was completely antagonized by pretreatment with the highly selective alpha 2-antagonist, idazoxan, as was alpha-MeHA by pretreatment with the highly selective histamine H3 antagonist, thioperamide. Taken together, the results are consistent with blockade by prejunctional alpha 2, histamine H3 and probably somatostatin receptors which may be coupled to inhibition of neuropeptide release. Because 5-HT1-like agonists, which are useful for treating migraine and related headaches, share similar inhibitory properties in this in vivo model, the significance of prejunctional alpha 2, histamine H3 and somatostatin receptors to treatment of vascular headaches is suggested.
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PMID:UK-14,304, R(-)-alpha-methyl-histamine and SMS 201-995 block plasma protein leakage within dura mater by prejunctional mechanisms. 128 76

The antiproliferative effects of somatostatin on hepatocytes stimulated by hepatocyte growth factor (HGF) or epidermal growth factor (EGF) were investigated using primary cultures of adult rat hepatocytes. Somatostatin inhibits HGF-induced (at a dose of 10 ng/mL) or EGF-induced (at a dose of 100 ng/mL) 3H-thymidine incorporation into hepatocytes in a dose-dependent manner (10(-10) to 10(-8) M). This inhibition was confirmed by autoradiography. The effect of somatostatin was nontoxic as judged by preserved albumin synthesis, a marker for differentiated hepatocyte function. In the presence or absence of somatostatin, neither HGF nor EGF significantly altered intracellular cyclic adenosine monophosphate (cAMP). We conclude that somatostatin is a potent inhibitor of HGF- or EGF-induced deoxyribonucleic acid synthesis in adult rat hepatocytes. The mechanism of this inhibition appears to be independent of cAMP. The significance of somatostatin in liver regeneration has yet to be assessed.
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PMID:Inhibition of DNA synthesis by somatostatin in rat hepatocytes stimulated by hepatocyte growth factor or epidermal growth factor. 134 60

The development of somatostatin analogs with anti-tumor effects has raised hopes for their use in various cancers and tumors of the central nervous system. However, for many therapeutic agents, access to normal brain is retarded by the blood-brain barrier (BBB) and to tumor tissues by a blood-brain tumor barrier (BBTB). We examined the ability of RC-160, a somatostatin analog with known anti-tumor activity, to cross the normal BBB and the BBTB in mice with brain sarcomas. In comparison with the normal BBB, the BBTB was about 10 times more permeable to the vascular marker albumin (radioactively labeled with 99mTc), but the BBTB still represents a substantial barrier. By contrast, the entry rate of RC-160, radioactively labeled with 125I, into brain sarcomas was 60 times higher than into normal brain tissue; more than 1% of the RC-160 injected i.v. was taken up by each gram of brain tumor. These results show that a brain tumor can selectively accumulate the potentially therapeutic agent RC-160.
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PMID:Selective uptake of the somatostatin analog RC-160 across the blood-brain tumor barrier of mice with KHT sarcomas. 136 Feb 72

Initial renal hypertrophy in experimental diabetes is prevented by administration of a long-acting somatostatin analogue octreotide (SMS). To investigate the long-term effects of SMS on renal hypertrophy and urinary albumin excretion (UAE), streptozotocin-diabetic and non-diabetic rats were treated with two daily subcutaneous injections of SMS (100 micrograms x 2) for six months. Untreated diabetic and non-diabetic animals were used as reference groups. No differences were seen between the two diabetic groups in respect to body weight, food intake, blood glucose levels, urinary glucose output, hemoglobin A1C(HbA1C), fructosamine, serum growth hormone (rGH) or creatinine clearance, but kidney weight (896 +/- 36 vs. 1000 +/- 24 mg, P less than 0.02), UAE (417 +/- 131 vs. 1098 +/- 187 micrograms/24 hr, P less than 0.02), kidney insulin-like growth factor I (IGF-I) (167 +/- 16 vs. 239 +/- 17 ng/g, P less than 0.01) and serum IGF-I (301 +/- 26 vs. 407 +/- 17 micrograms/liter, P less than 0.01) were all reduced in the SMS-treated diabetic animals when compared to the untreated diabetic group. In non-diabetic rats SMS reduced body weight (274 +/- 3 vs. 293 +/- 5 g, P less than 0.01), kidney weight (695 +/- 9 vs. 764 +/- 17 mg, P less than 0.01), UAE (83 +/- 29 vs. 364 +/- 114 micrograms/24 hr, P less than 0.02), kidney IGF-I (202 +/- 12 vs. 280 +/- 12 ng/g, P less than 0.01), serum IGF-I (428 +/- 21 vs. 601 +/- 54 micrograms/liter, P less than 0.01) and serum rGH (67 +/- 6 vs. 126 +/- 27 micrograms/liter, P less than 0.05) when compared to untreated controls. When kidney weights were expressed in relation to body weight no difference was found between SMS-treated and untreated controls, while the difference between SMS-treated and untreated diabetic animals was still present (P less than 0.01). In conclusion, chronic administration of SMS has abating effects on diabetic renal hypertrophy and UAE, and thus indicates that SMS may reduce development of diabetic kidney lesions in experimental diabetes. The long-term suppressive effects of SMS on renal enlargement and UAE may in part be mediated through reduction in circulating and kidney IGF-I levels.
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PMID:Octreotide administration in diabetic rats: effects on renal hypertrophy and urinary albumin excretion. 151 3

In NIH 3T3 cells the c-fos gene is induced rapidly and transiently by cAMP. As shown by the analysis of 3T3 cells stably transfected with promoter mutants of the human c-fos gene this induction does not depend on the dyad symmetry element (position -320 to -300), but involves at least two other non-related sites: an element located around position -60 resembling the cAMP response element of the fibronectin and somatostatin genes (which has been described before), and an element located between positions +18 and +38. Destruction of one or the other element in the c-fos gene reduces cAMP inducibility. The cAMP response of c-fos promoter CAT gene constructs also depends on these elements in transient transfection assays. When cloned in front of the albumin TATA box, both elements independently mediate cAMP inducibility. These elements do not bind the same protein as shown in gel retardation analyses, suggesting that two different cAMP inducible factors mediate the activation of the c-fos gene by cAMP.
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PMID:A new cAMP response element in the transcribed region of the human c-fos gene. 165 78

We evaluated the effect of a somatostatin analogue (SMS 201-995) on diabetic nephropathy using urinary albumin excretion as a marker in a streptozocin-induced diabetic unilateral nephrectomized rat model. Nondiabetic rats were injected with either 0.9% sodium chloride (NaCl) (n = 10) or SMS (n = 10). Diabetic rats were also injected with either 0.9% NaCl (n = 10) or SMS (n = 10). The control saline and SMS groups showed significant increases in urinary albumin excretion (UAE) and albumin clearance. The diabetic saline-treated rats showed no significant changes in UAE or albumin clearance. The diabetic SMS-treated rats showed significant decreases in UAE (151 +/- 76 mg/day/kg to 98 +/- 46, P less than .005) and albumin clearance (5.85 +/- 3.34 mL/day/kg to 3.63 +/- 1.73, P less than .01). There was no significant difference in kidney weight between the two control groups, but a significant difference was found between the two diabetic groups (3.35 +/- 0.39 g vs. 2.68 +/- 0.26 g, P less than .001). The results suggest that in early diabetes with renal hyperfiltration and hypertrophy, the administration of SMS may prevent progression to late diabetic nephropathy.
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PMID:Effect of a somatostatin analogue (SMS 201-995) on renal function and urinary protein excretion in diabetic rats. 177 39

Hormonal changes and whole blood free amino acid levels and their relation to renal function were measured in 12 insulin-dependent diabetic patients after two 10-day periods with a diet consisting of 10% and 20% respectively of the energy as protein. The patients were 15-21 years old and mean duration of diabetes was 12 (5-20) years. Glomerular filtration rate, renal plasma flow, and albumin excretion rate were measured together with plasma concentrations of glucagon, growth hormone, insulin-like growth factor 1 (IGF-1), somatostatin, serum insulin and free amino acids in blood. Glomerular filtration rate was 123 +/- 3 ml/min/1.73 m2 on high protein diet and 113 +/- 3 ml/min/1.73 m2 on low protein diet (p = 0.02). Renal plasma flow was unchanged. Glucagon, IGF-1, branch chained amino acids (BCAA), tyrosine, phenylalanine, lysine, and methionine were increased after the high protein diet. Growth hormone, somatostatin, insulin, and other amino acids remained unchanged. The increase in glomerular filtration rate was significantly correlated to the increase in glucagon, isoleucine, and valine (glucagon r = 0.71, p = 0.01, isoleucine r = 0.59, p = 0.04, valine r = 0.62, p = 0.03). In a multiple regression model the increase in glomerular filtration correlated most strongly to the increase in isoleucine, followed by valine and glucagon. Together these variables explained 88% of the total variance of the change in glomerular filtration rate (r2 = 0.88, p = 0.001). Albumin excretion rate was correlated to IGF-1 (r = 0.86, p less than 0.001) on the high protein diet.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Indications that branched chain amino acids, in addition to glucagon, affect the glomerular filtration rate after a high protein diet in insulin-dependent diabetes. 180 76

We have investigated the transcriptional activity of human cytomegalovirus, herpes thymidine kinase, human chorionic gonadotropin alpha, somatostatin, immunoglobulin kappa chain, alpha crystallin, albumin and interferon-beta promoters in the fission yeast Schizosaccharomyces pombe. Among these, the human cytomegalovirus, human chorionic gonadotropin alpha, and somatostatin promoters were found to be very active, approximately 11-, 9-, and 0.9-fold as active as the SV40 early promoter, respectively. The remainder of the promoters studied were weak, having only 10-20% of the SV40 promoter activity. Primer extension analysis showed that the strong promoters initiated transcription in S. pombe at the same sites as in mammalian cells, indicating the high similarity between both transcriptional systems.
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PMID:Human chorionic gonadotropin alpha and human cytomegalovirus promoters are extremely active in the fission yeast Schizosaccharomyces pombe. 197 20


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