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)

A sensitive and specific radioimmunoassay for somatostatin is described. With the use of this system, somatostatin release from incubated rat pancreatic islets and perfused rat pancreases has been studied in vitro. Both arginine and glucose, known modulators of insulin and glucagon secretion, were found to stimulate somatostatin release. These results provide additional support for the concept that somatostatin may act as a local regulator of pancreatic A cell function.
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PMID:Radioimmunoassay of somatostatin and its application in the study of pancreatic somatostatin secretion in vitro. 43 2

Somatostatin (SRIF) has been tested for its actions on the central nervous system to affect glucoregulation. In doses ineffective when given systemically , SRIF and SRIF analogs given intracisternally (ic) reduce hyperglycemia and hyperglucagonemia after ic bombesin administration. The SRIF analog, des-AA1, 2, 4, 5, 12, 13-[D-Trp8]SRIF, decreases plasma insulin and elevates plasma glucose and glucagon when given systemically. However, when given ic, this peptide prevents the rise in glucose and glucagon after ic bombesin administration and is 10 times more potent than SRIF in reducing bombesin-induced hyperglycemia. Other analogs of SRIF and various unrelated peptides were found to be ineffective in reducing bombesin-induced hyperglycemia. des-AA1, 2, 4, 5, 12, 13-[D-Trp]SRIF prevented the hyperglycemia induced by surgical stress or by ic administration of beta-endorphin or carbacol. des-AA1, 2, 4, 5, 12, 13-[D-Trp]SRIF given ic did not prevent hyperglycemia induced by systemic administration of epinephrine, arginine, or glucagon. These studies suggest that SRIF and its analogs may act within the brain to affect glucoregulation.
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PMID:Somatostatin: central nervous system actions on glucoregulation. 44 91

In order to elucidate the role of endogenous somatostatin in the control of insulin and glucagon secretion, glucagon- or insulin-induced somatostatin release from the isolated perfused rat pancreas was studied. Immunoreactive somatostatin was persistently released for 60 min in response to perfusion by 5.5 mM glucose at concentrations ranging between 10 and 15 pg/ml. The addition of glucagon (10(-8), 10(-7), and 10(-6) M) caused a dose-related increase of somatostatin release. In contrast, insulin release, especially its first phase, was suppressed when concentrations of glucagon were increased. The addition of insulin (10(-7) M and 10(-6) M) had no significant effect on somatostatin and glucagon release. These results raise the possibility that endogenous somatostatin and glucagon together regulate insulin secretion, suggesting a close interrelationship between insulin, glucagon, and somatostatin secretion within the islet.
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PMID:Somatostatin release from isolated perfused rat pancreas. Possible role of endogenous somatostatin on insulin release. 44 17

Bombesin acts within the brain to produce a prompt and sustained hyperglycemia, hyperglucagonemia, and relative or absolute hypoinsulinemia. Bombesin does not decrease plasma glucose turnover. Acute adrenalectomy but not hypophysectomy prevents hyperglycemia and hyperglucagonemia after intracisternal administration of bombesin. Administration of bombesin into the lateral ventricle of awake, unrestrained animals results in elevation of plasma glucose, preceded by a significant increase in plasma epinephrine and no increase in plasma norepinephrine or dopamine. Systemic administration of somatostatin prevents bombesin-induced hyperglycemia and hyperglucagonemia. These data support the conclusion that bombesin acts within the brain to increase sympathetic outflow resulting in increased adrenalmedullary epinephrine secretion, followed by depression of plasma insulin and elevation of plasma glucagon and glucose.
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PMID:Central nervous system action of bombesin: mechanism to induce hyperglycemia. 46 25

The effects of somatostatin and a long acting, glucagon selective somatostatin analog (des-Ala1Gly2[His4,5-D-TrP8]-somatostatin) used studied during arginine tolerance tests in normal anaesthetized rats. Arginine infusion in control animals resulted in a rapid increase in plasma insulin and glucagon, and an increase of 15 +/- 5 mg/dl in plasma glucose. Somatostatin infusion (1 mg/kg/h) resulted in suppression of basal insulin secretion and a decrease in arginine-induced insulin and glucagon release. Glucose levels increased rapidly during the combined arginine-somatostatin infusion reaching a peak of 72 +/- 10 mg/dl above basal levels. Similar results were obtained when somatostatin was injected SC (1 mg/kg) at times 0, 15, 30, and 45 minutes (arginine infused from 30-60 minutes). A single injection (1 mg/kg) of the long-acting somatostatin analogue resulted in significant inhibition of basal insulin and glucagon release; during arginine infusion glucagon levels rose only slightly, the insulin response was, however, nearly normal, and only a small arginine-induced increase in glucose levels was observed. Carbohydrate absorption was not influenced by either somatostatin or the analogue.
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PMID:Effect of a long acting glucagon selective somatostatin analogue on plasma glucose, insulin and glucagon levels in the anaesthetized rat during arginine infusion. 46 54

To examine the roles of glucagon and insulin in exercise, four sheep were run on a treadmill with and without simultaneous infusion of somatostatin (SRIF), a peptide that suppresses glucagon and insulin secretion. SRIF infusion suppressed the exercise-induced rise in plasma glucagon during both moderate (5--5.5 km/h) and strenuous exercise (7.0 km/h). In addition, SRIF prevented the rise insulin concentrations during moderate exercise. During strenuous exercise, insulin concentrations were depressed in both groups. The infusion of SRIF was associated with a reduction in exercise-induced glucose production, as determined by infusion of [6-3H]glucose, during the first 15 min of both moderate and strenuous exercise compared to controls. Beyond 15 min glucose production was not significantly altered by SRIF infusions. These data are consistent with glucagon having an immediate, but only transient, stimulatory effect on the exercise-induced hepatic glucose production.
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PMID:Effect of somatostatin on plasma glucagon and insulin, and glucose turnover in exercising sheep. 46 84

The effects of two [D-Cys14]-analogues of somatostatin on basal plasma levels of glucagon, insulin and glucose were determined in unanaesthetized rats to re-examine a glucagon-selective action of these peptides which has been claimed by others. Somatostatin, [D-Cys14]-somatostatin and [D-Trp8, D-Cys14]-somatostatin caused a short-lasting, dose-dependent decrease of plasma glucagon and insulin but they had no significant influence on plasma glucose. Glucagon and insulin reached the nadir 2 min after intravenous injection of the peptides (dose range 1--10 micrograms/kg) or 5 min after subcutaneous administration (30 and 300 micrograms/kg). At the nadir, insulin was decreased to a greater extent than glucagon and the effecer the nadir and at high doses, the time-course of some effects of the analogues on either glucagon or insulin differed from that of somatostatin. Thus, these [D-Cys14]-analogues may show partial kinetic dissociation of effects on glucagon and insulin but they are not truly selective inhibitors of glucagon release.
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PMID:Non-selective inhibition of basal glucagon release by [D-Cys14]-analogues of somatostatin in the rat. 46 62

The effect of intravenous somatostatin on blood levels of metabolites and hormones has been examined in normal subjects who performed a 30-minute period of bicycle exercises at 70% maximal exercise capacity. The results have been compared with control studies in the same subjects. Measurements were made of blood levels of lactate, glucose, free fatty acids, glycerol, acetoacetate, 3-hydroxybutyrate, insulin, glucagon, growth hormone (hGH) and prolactin. Growth hormone and glucagon release were suppressed during exercise with somatostatin and there was a subsequent elevation during recovery. There was slight post-exercise depression of insulin, but no alteration of plasma prolactin secretion. Blood glucose was reduced during exercise with somatostatin and increased during recovery. The elevation of ketone bodies after exercise was greater in the investigation with somatostatin, but there were no significant changes in other metabolites. Somatostatin, although causing inhibition of hGH release, appeared to have no significant effect upon fatty acid mobilization during exercise.
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PMID:The effect of somatostatin on metabolic and hormonal changes during and after exercise. 47 77

Growth hormone (GH) secretion has been studied in two patients with the carcinoid syndrome during glucose loading and growth hormone-release inhibiting hormone (GHRIH, somatostatin) infusion. Both patients had elevated fasting GH levels which were not suppressed by glucose; GH levels fell rapidly during GHRIH infusion. One patient also had hyperprolactinaemia with galactorrhoea and the prolactin (PRL) levels were unaltered by GHRIH. The association between carcinoid tumours and abnormalities of GH and PRL secretion is discussed.
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PMID:Effect of somatostatin on abnormal growth hormone and prolactin secretion in patients with the carcinoid syndrome. 47 84

When isolated rat liver cells were incubated in the presence of vasoactive intestinal peptide at the concentrations ranging from 0.2 microgram to 2 micrograms per ml, glycogenolysis was maximally stimulated within 15 min. However, somatostatin inhibited the liver glycogenolysis. The combined addition to the incubation medium showed that insulin and somatostatin inhibited the stimulated glycogenolysis induced by vasoactive intestinal peptide, while vasoactive intestinal peptide plus secretin showed no additive effect on glycogenolysis, as compared with single the addition of vasoactive intestinal peptide. On the other hand, the additon of glucagon to vasoactive intestinal peptide showed additive effects on glycogenolysis. These results suggest that the receptor site for vasoactive intestinal peptide may be distinguishable from that for glucagon. Extracellular calcium ions were demonstrated to play an important role in the modulation of vasoactive intestinal peptide-induced glycogenolysis. The evidence presented in this paper indicates that glucose metabolism may be partly regulated by the direct action of vasoactive intestinal peptide on hepatocytes, which is referred to as an enterohepatic axis and that the axis is inhibited by insulin and somatostatin.
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PMID:Effects of vasoactive intestinal peptide on glycogenolysis in cultured liver cells. 47 14


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