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 total of 24 patients with endocrine neoplasms of the pancreas were clinicopathologically and immunohistochemically studied. They consisted of 18 patients with adenoma and 6 with carcinoma. Of the 24 patients, 13 developed attacks of hypoglycemia due to hyperinsulinemia, and 1 developed an uncontrollable duodenal ulcer caused by the hypersecretion of gastrin, however, the remaining 10 were asymptomatic. No prediction could be made as to the site of origin of the tumors. A clear difference was seen between adenoma and carcinoma in the size of the mass, the mean greatest diameter of the 18 adenoma cases being 1.7 cm, while that of the 6 carcinoma cases was 7.3 cm. One of the 13 insulinomas and a gastrinoma was malignant, while all 24 tumors were positive for neuron-specific enolase. The 13 insulinomas were diffusely positive for insulin and 5 were also shown to be focally immunoreactive for gastrin, with 3 also being immunoreactive for somatostatin and 2 for pancreatic polypeptide. The gastrinoma showed immunoreactivity for somatostatin, insulin, pancreatic polypeptide, and glucagon in addition to a positivity to gastrin. The above findings thus indicate the multiple hormone synthesis of endocrine neoplasms of the pancreas.
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PMID:Endocrine neoplasms of the pancreas: a clinicopathologic study of 24 cases and immunohistochemical remarks. 139 40

To determine the relationship between decreases in glucose and metabolic regulation in the absence of counterregulatory hormones, we infused overnight-fasted, conscious, adrenalectomized dogs (lacking cortisol and EPI) with somatostatin (to eliminate glucagon and growth hormone) and intraportal insulin (30 pmol.kg-1.min-1), creating arterial insulin levels of approximately 2000 pM. Glucose was infused during one 120-min period, two 90-min periods, and one 45-min period to establish levels of 5.9 +/- 0.1, 3.4 +/- 0.1, 2.5 +/- 0.1, and 1.7 +/- 0.1 mM, respectively. NE levels were 1.24 +/- 0.23, 1.85 +/- 0.27, 2.04 +/- 0.26, and 2.50 +/- 0.20 nM, respectively. During the euglycemic control period, the liver took up glucose (7.5 +/- 1.9 mumol.kg-1.min-1), but hypoglycemia triggered successively greater rates of net hepatic glucose output (3.0 +/- 0.7, 4.6 +/- 0.9, and 6.9 +/- 1.4 mumol.kg-1.min-1). Total gluconeogenic precursor uptake by the liver increased with hypoglycemia. Intrahepatic gluconeogenic efficiency rose progressively (by 106 +/- 42, 199 +/- 56, and 268 +/- 55%). Both glycerol and NEFA levels rose, indicating lipolysis was enhanced. Net hepatic NEFA uptake and ketone production increased proportionally, but the ketone level rose only with severe hypoglycemia. In conclusion, despite marked hyperinsulinemia and the absence of glucagon, EPI, and cortisol, we observed that lipolysis and glucose and ketone production increase in response to decreases in glucose. This suggests that neural and/or autoregulatory mechanisms can play a role in combating hypoglycemia.
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PMID:Relationship between decrements in glucose level and metabolic response to hypoglycemia in absence of counterregulatory hormones in the conscious dog. 139 5

To compare the effect on glucose recovery after insulin-induced hypoglycaemia of intramuscular genetically engineered glucagon, intramuscular glucagon from pancreatic extraction and intravenous glucose, we examined 10 healthy subjects during blockage of glucose counterregulation with somatostatin, propranolol and phentolamine. Each subject was studied on three separate occasions. Thirty min after a bolus injection of 0.075 iu soluble insulin per kilogram body weight the subjects received one of the following treatments: 1 mg glucagon from pancreatic extraction intramuscularly; 1 mg genetically engineered glucagon intramuscularly; and 25 g glucose intravenously, respectively. The two glucagon preparations induced an equally rapid increase in plasma glucose. This was due to an abrupt (within 4 min) and equal increase in glucose appearance rate. The increases in both plasma glucose and in glucose appearance rate were far more protracted after i.m. glucagon than after i.v. glucose. These results suggest that genetically engineered glucagon and glucagon from pancreatic extraction have a similar effect on hepatic glucose production rate. Due to the protracted effect of intramuscular glucagon, a combined treatment consisting of both intravenous glucose and intramuscular glucagon may be more effective in the treatment of hypoglycaemia than any of these given alone.
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PMID:The effect of genetically engineered glucagon on glucose recovery after hypoglycaemia in man. 149 86

We previously reported that patients with idiopathic reactive hypoglycemia (plasma glucose concentration lower than 2.5 mmol/L 2-4 h after the ingestion of 75 g of glucose) display reduced or absent counterregulatory response of the glucagon secretion and increased insulin sensitivity. In order to examine the effect of glucagon on the increased insulin sensitivity in these patients, 12 subjects with idiopathic reactive hypoglycemia underwent a two-step hyperinsulinemic (1 mU/kg.min) euglycemic glucose clamp and were compared with 12 normal control subjects matched for age, weight and sex. During the first step of the glucose clamp (only insulin + glucose infusion) the patients with Idiopathic Reactive Hypoglycemia required higher glucose infusion rates to maintain euglycemia than normal subjects (9.09 +/- 0.29 mg/kg. min vs 7.61 mg/kg.min). When basal glucagon secretion was replaced (+ somatostatin and glucagon, second step of the clamp) the glucose infusion rates required to maintain euglycemia in patients with Idiopathic Reactive Hypoglycemia significantly decreased (to 7.17 +/- 0.40 mg/kg.min) and resulted similar to normal subjects (7.64 +/- 0.41 mg/kg.min). Thus, in patients affected by Idiopathic Reactive Hypoglycemia, glucagon secretion may play an important role in the pathogenesis of the increased insulin sensitivity and hypoglycemia.
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PMID:Idiopathic reactive hypoglycemia: a role for glucagon? 151 17

Growth hormone (GH) hypersecretion is well documented in insulin-dependent diabetes mellitus (IDDM). Somatostatin inhibits GH in acromegalics and healthy subjects although data on its inhibitory effects on high GH levels in IDDM patients are controversial. The effect of treatment with the somatostatin analogue octreotide ("Sandostatin") on GH secretion, IGF1 levels and metabolic control was investigated in insulin-dependent diabetics. Growth hormone and blood glucose were measured at hourly intervals whilst IGF-I was measured every 6 hours during the 24-h period before and after 7 days' treatment with octreotide (200 micrograms subcutaneously three times daily) in 10 C-peptide negative diabetics. Octreotide significantly reduced mean 24 h GH profile (7.2 +/- 0.7 mU/L before; 5.2 +/- 0.5 mU/L on octreotide, p less than 0.01), IGF-I levels (0.62 +/- 0.06 before; 0.47 +/- 0.05 on octreotide, p less than 0.005) mean 24 h blood glucose (14.4 +/- 0.5 mmol/L before; 12.6 +/- 0.4 mmol/L on octreotide, p less than 0.001) and daily insulin requirements (44.8 +/- 3.0 IU before; 37.2 +/- 3.0 IU on octreotide, p less than 0.02). The shape of 24 h GH profile curve changed significantly on octreotide treatment (p less than 0.05) when it consisted of three nadirs and three peaks closely linked with the time of octreotide administration. Moderate (abdominal discomfort) to severe hypoglycaemia) transient side effects have been observed in all treated patients. The results of this study showed that short-term treatment with octreotide given s. c. every eight hours modulates the pattern of GH secretion in C-peptide negative insulin-dependent patients.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The effect of the somatostatin analogue octreotide on growth hormone secretion in insulin-dependent diabetics without residual insulin secretion. 151 89

To determine whether differences in the neuroendocrine control of GH are present between children and adult subjects, the GH response to GHRH (1 microgram/kg) (group 1), insulin-induced hypoglycemia (0.1 U/kg iv) (group 2), clonidine (150 micrograms/m2 po) (group 3) and iv arginine (0.5 g/kg in 30 min) (group 4) after GHRH pretreatment (1 microgram/kg) was studied in 26 short-stature normal children (mean age 10.2 years). The results were compared with historical data in adults. No differences were present among mean peak GH levels after the first and second stimuli in groups 1, 2 and 3, while in group 4 the GH response to arginine administration was lower than that obtained after the initial GHRH (0.43 +/- 0.04 vs 0.9 +/- 0.13 nmol/l). Moreover, comparing the GH peak values following the second stimulus, it appears that the greatest GH responses were elicited by GHRH (1.31 +/- 0.23 nmol/l) and clonidine (1.11 +/- 0.22 nmol/l), while the lowest was elicited by arginine (0.43 +/- 0.04 nmol/l). In adults, sequential GHRH administration leads to inhibition of the response of the somatotropes, probably mediated by an increase in hypothalamic somatostatin. Our results confirm that after GHRH prestimulation GHRH elicits a significant GH response suggesting that activation of the somatostatinergic tone is less effective in children. This hypothesis also explains the low GH response to arginine which acts selectively through somatostatin inhibition.
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PMID:GH response to GHRH, insulin, clonidine and arginine after GHRH pretreatment in children. 154 13

Severe reactive hypoglycaemia was confirmed in a non-diabetic male patient by a counter-regulatory hormone (GH, cortisol and catecholamine) response to profound hypoglycaemia induced by an intravenous glucose load. There was also evidence of disordered pancreatic islet cell paracrine regulation with hyperinsulinaemia and absent glucagon response to hypoglycaemia. A defect in the patient's hepatic glucose-6-phosphatase enzyme system was documented. Because of severe symptoms, dietary control was insufficient, but the patient responded clinically and biochemically to 18 months of oral diazoxide therapy. He also showed good biochemical response to a single dose (100 micrograms IM) of the somatostatin analogue octreotide.
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PMID:Reactive hypoglycaemia in association with disordered islet function and abnormal hepatic glucose-6-phosphatase activity: response to diazoxide. 183 18

Chromogranin-A (CgA) is an acidic soluble protein with a virtually ubiquitous occurrence in normal human neuroendocrine tissues. Of the many potential tissue sources of CgA immunoreactivity, which contribute to basal (unstimulated) circulating CgA? To explore this question we studied the effects of selective and nonselective suppression of secretion at several sites within the neuroendocrine system. Selective disruption of sympathetic outflow by trimethaphan decreased basal CgA by 25%, suggesting that sympathetic neurons contribute to circulating CgA. Plasma CgA in patients with unilateral and bilateral adrenalectomy fell within the range observed in normal subjects, weighing against the adrenal medulla as a major source of basal circulating CgA. Selective suppression of a variety of anterior and posterior pituitary cell types decreased plasma levels of the usual resident peptide hormones, but left plasma CgA unperturbed. After propranolol treatment, plasma CgA remained unaltered. Secretin suppressed plasma PTH and calcitonin, but did not alter plasma CgA levels. On the other hand, widespread nonselective suppression of a variety of neuroendocrine secretory cells by somatostatin decreased plasma CgA by 48%. Plasma catecholamines were unaltered by somatostatin infusion, suggesting that somatostatin inhibited CgA release from nonsympathoadrenal sources. During the infusion of somatostatin, the plasma epinephrine increment in response to insulin-induced hypoglycemia was maintained, and plasma CgA did not fall, nor did it rise after somatostatin cessation. Taken together, these findings suggest that somatostatin did not inhibit transport of stimulation-released CgA from the adrenal medulla to the circulation. In conclusion, although the adrenal medulla is the major tissue source of CgA immunoreactivity in man, other neuroendocrine sites, including sympathetic axons and multiple endocrine glands, appear to influence the basal circulating concentration of CgA.
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PMID:Suppression of chromogranin-A release from neuroendocrine sources in man: pharmacological studies. 167 83

In order to establish whether endogenous opioids play a role in the control of arginine vasopressin (AVP) response to insulin-induced hypoglycemia by interacting with somatostatin (SRIH), seven normal men were submitted to an insulin (0.15 U/kg) tolerance test (ITT) in the presence or absence of naloxone (10 mg in an i.v. bolus), SRIH (4.1 micrograms/min x 90 min) or the combination of the two substances. Plasma AVP concentrations rose significantly during ITT. The AVP response remained unchanged in the presence of naloxone, whereas it was significantly reduced by the treatment with SRIH. When both SRIH and naloxone were given, the hypoglycemia induced AVP rise was similar to that observed in the control test. These results indicate the involvement of naloxone sensitive endogenous opioids in the mechanism underlying SRIH inhibitory action, but not in the mediation of the AVP response to hypoglycemia.
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PMID:Endogenous opioid mediation of somatostatin inhibition of arginine vasopressin release evoked by insulin-induced hypoglycemia in man. 167 42

To assess the role of catecholamines in the prevention of hypoglycemia during moderate exercise (approximately 60% peak O2 consumption for 60 min), normal humans were studied with combined alpha- and beta-adrenergic blockade and with adrenergic blockade while changes in insulin and glucagon were prevented with the islet clamp technique (somatostatin infusion with insulin and glucagon infused at fixed rates). The results were compared with those from an islet clamp alone study. In contrast to a comparison study (saline infusion), adrenergic blockade resulted in a small initial decrease in plasma glucose during exercise, from 5.0 +/- 0.2 to 4.4 +/- 0.2 mmol/l (P less than 0.01), but the level then plateaued. There was a substantial exercise-associated decrement in plasma glucose when insulin and glucagon were held constant, i.e., from 5.5 +/- 0.2 to 3.4 +/- 0.2 mmol/l (P less than 0.0001), but the level again plateaued. However, when insulin and glucagon were held constant and catecholamine actions were blocked simultaneously, progressive hypoglycemia, to 2.6 +/- 0.6 mmol/l (P less than 0.001), developed during exercise. Hypoglycemia was the result of an absent increase in glucose production and an exaggerated initial increase in glucose utilization. Thus we conclude that sympathochromaffin activation plays a minor role when insulin and glucagon are operative, but a catecholamine, probably epinephrine, becomes critical to the prevention of hypoglycemia during exercise when changes in insulin and glucagon do not occur.
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PMID:Catecholamines in prevention of hypoglycemia during exercise in humans. 167 42


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