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)

Excessive secretion of peptides causes the clinical syndromes associated with functional gastro-intestinal tumours. The somatostatin analogue octreotide acetate inhibits peptide release from a variety of tumours. This study investigated the interactions of calcium and somatostatin analogues on peptide release in two patients, one with a glucagonoma (patient A) and one with an insulinoma (patient B). Peptide responses were evaluated before (fasting levels) and after provocative tests (a 4-hour calcium infusion, an intravenous tolbutamide infusion, a secretin bolus and a standard test meal) in the absence and presence of octreotide acetate treatment (100 micrograms subcutaneously every 8 h). Patients A and B had elevated fasting plasma levels of glucagon and insulin, respectively, which were reduced by octreotide therapy by 73 and 50%, respectively. The peak provoked levels and calculated values for peptide synthesis were lower after octreotide therapy. In both patients, tolbutamide provoked most peptide release, and calcium infusion was the least susceptible to the effects of octreotide therapy. Calcium appears to inhibit octreotide suppression of glucagon and insulin secretion in patients with glucagonoma and insulinoma, respectively. Calcium may stimulate peptide release from endocrine tumours by suppressing the inhibitory effects of endogenous somatostatin. Normalisation of serum calcium, either surgically or pharmacologically, may improve the effectiveness of somatostatin analogue therapy.
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PMID:Calcium reverses octreotide inhibition of insulin and glucagon levels in patients with insulinoma and glucagonoma. 881 73

Since December 1993, in the 1st Nuclear Medicine Service of the University of Padua, eleven somatostatin-receptor scintigraphic studies with 111In-labelled pentetreotide have been performed. The patients (6 men and 5 women, age 28-68, mean 45 years) were affected by a variety of tumors which supposedly express somatostatin receptors: 2 meningotheliomatous meningiomas post-surgery; 2 glucagonomas with liver metastases observed on CT; 2 patients with suspicion of insulinoma; 2 carcinoids, one after surgery; 1 ectopic-ACTH Cushing's syndrome; 1 intracranial germinoma, post-surgery, in whom the study was requested to evaluate a doubtful finding of pulmonary metastatic lesion on CT; and 1 acromegaly showing, on MRI, and empty sella turcica occupied by and extraflexion of the lower portion of the chiasmatic cisterna without signs of adenoma and the sphenoidal sinus occupied by tissue wit inflammmatory characteristics. Somatostatin-receptor whole body scintigraphy was performed 4 and 24 hours after intravenous injection of 110 MBq 111In-pentetreotide (Octreoscan 111); spot images were acquired when judged necessary. In one case of glucagonoma, a tomographic scan (SPECT) was also performed to better evaluate the spatial relationship between the primitive pancreatic tumor and surrounding tissues. Focal accumulation of 111In-pentetreotide was scintigraphically detected in 5 of the 11 cases. Intense uptake of the radiopharmaceutical was observed in the meningiomas, in the glucagonomas with liver metastases, and in the case of acromegaly, corresponding to a GH-secreting adenoma. The negative scans seem to be true negative scans with the possible exception of one patient with a still unconfirmed suspicion of insulinoma, still not confirmed.
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PMID:Whole body and tomographic scan with 111In-pentetreotide: preliminary data. 900 69

Glucagonoma is an uncommon, challenging but treatable disease with varied manifestations. Despite its predominantly malignant nature, prolonged symptom-free survival can be achieved using a targeted combination of surgery, hepatic artery embolization and somatostatin analogues. Given the difficult management issues, an initial assessment in an experienced tertiary referral centre may also be of benefit. This chapter has looked at the long-term follow-up of 18 such patients over a 25-year period. Given the rarity of the tumour, the numbers are small, but valuable lessons can be learnt from the study in the clinical management of these patients.
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PMID:Gastrointestinal endocrine tumours. Glucagonomas. 911 18

Glucagonoma is a neuroendocrine tumor of pancreatic alpha cells manifested by necrolytic migratory erythema, hyperglucagonemia, glucose intolerance, weight loss, anemia and hypopaminoacidemia. We report a case of glucagonoma in a 38 years-old patient diagnosed by the presence of a pancreatic tumor, liver metastasis, weight loss, glucose intolerance, necrolytic migratory erythema, hyperglucagonemia (1400 pg/ml; normal < 200 pg/ml) and histologic demonstration of glucagon and neurospecific enolase by immunocytochemical reaction. Actual therapeutic of glucagonoma includes surgery, chemotherapy, somatostatin or octreotide for control of the symptoms, and more recently alpha-interferon was suggested.
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PMID:[Glucagonoma: case report and literature review]. 920 30

Inhibition of pancreatic glucagon secretion has been reported to be mediated by glucose, insulin and somatostatin. As no human pancreatic alpha-cell lines are available to study in vitro the relative importance of insulin and glucose in the control of pancreatic glucagon release, we investigated a patient presenting with a malignant glucagonoma who underwent surgical resection of the tumour. Functional somatostatin receptors were present as octreotide administration decreased basal glucagon and insulin secretion by 52 and 74%, respectively. The removed tumour was immunohistochemically positive for glucagon, chromogranin A and pancreatic polypeptide but negative for insulin, gastrin and somatostatin. The glucagonoma cells were also isolated and cultured in vitro. Incubation experiments revealed that change from high (10 mM) to low (1 mM) glucose concentration was unable to stimulate glucagon secretion. A dose-dependent inhibition of glucagon release by insulin was however, observed at low glucose concentration. These findings demonstrate that insulin could inhibit glucagon secretion in vitro in the absence of elevated glucose concentrations. These data suggest, as observed in vivo and in vitro in several animal studies, that glucopenia-induced glucagon secretion in humans is not mediated by a direct effect of low glucose on alpha-cells but possibly by a reduction of insulin-mediated alpha-cell suppression and/or an indirect neuronal stimulation of glucagon release.
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PMID:In vivo and in vitro effects of somatostatin and insulin on glucagon release in a human glucagonoma. 923 Oct 61

Under physiological conditions, the pancreas scarcely influences the function of the cardiovascular system, although the hormones produced in the healthy pancreas (insulin, glucagon and somatostatin) affect the myocardial contractility in pharmacological doses. Among the diseases of the pancreas, the pancreatic tumours (insulinoma, glucagonoma and vipoma), furthermore the acute and chronic pancreatitis involve cardiovascular complications, which influence the outcome of the disease. Although the clinical picture is dominated by the metabolic changes of the excessively produced hormones in pancreatic tumours, the cardiac and vascular effects of the hormones may be considerable. In acute necrotizing pancreatitis, enzymes released from the pancreas and inflammatory mediators transform acute necrotizing pancreatitis into "multiple organ disease"; one of the important forms of this disease is the cardiovascular shock syndrome. One of the best-known complications of chronic pancreatitis is the pancreoprive diabetes mellitus, and beside that other, nonspecific cardiac alterations (e.g. ECG-changes) may occur.
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PMID:[Cardiovascular complications of pancreatis diseases]. 928 88

We report three cases of malignant glucagonoma with necrolytic migratory erythema as the first clinical symptom. Long-acting somatostatin analogue was the first step of a multimodal therapeutic strategy which included surgical resection of the primary tumour in every case. Liver metastases which were present in two patients were treated by hepatic arterial chemoembolization and systemic chemotherapy in one case and by liver resection for cytoreduction and hepatic arterial chemoembolization in another case. Skin lesions resolved in all three patients.
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PMID:Necrolytic migratory erythema, first symptom of a malignant glucagonoma: treatment by long-acting somatostatin and surgical resection. Report of three cases. 987 Jul 35

The hypothalamic satiety peptide CART (cocaine and amphetamine regulated transcript) is expressed at high levels in anorectic rat glucagonomas but not in hypoglycemic insulinomas. However, a non-anorectic metastasis derived from the glucagonoma retained high CART expression levels and produced circulating CART levels comparable to that of the anorectic tumors. Moreover, distinct glucagonoma lines derived by stable HES-1 transfection of the insulinoma caused severe anorexia but retained low circulating levels of CART comparable to that of insulinoma bearing or control rats. Islet tumor associated anorexia and circulating CART levels are thus not correlated, and in line with this peripheral administration of CART (5-50 mg/kg) produced no effect on feeding behavior. In the rat two alternatively spliced forms of CART mRNA exist and quantitative PCR revealed expression of both forms in the hypothalamus, in the different islet tumors, and in the islets of Langerhans. Immunocytochemistry as well as in situ hybridization localized CART expression to the somatostatin producing islet D cell. A potential endocrine/paracrine role of islet CART remains to be clarified.
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PMID:The hypothalamic satiety peptide CART is expressed in anorectic and non-anorectic pancreatic islet tumors and in the normal islet of Langerhans. 1021 34

Glucagonoma and somatostatinoma are tumors which produce the respective hormone. When these peptides are also secreted into the circulation the clinical syndromes are characterized by the signs and symptoms due to hormone overproduction. In case of the glucagonoma-syndrome diabetes and typical skin lesions are dominating while patients with the somatostatinoma syndrome have diabetes frequently associated with steatorrhea. Surgical resection of the tumor and its metastases as far as possible is the therapy of choice. For symptomatic relief and inhibition of the growth of the metastases interferon-a and somatostatin analogues can be employed.
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PMID:[Glucagonoma--somatostatinoma]. 1044 13

In patients with gastro-enteropancreatic neuroendocrine tumours the localization of all the neoplastic lesions and an accurate staging of the diseases have important therapeutic implications. Somatostatin receptor scintigraphy with In-111 pentatreotide has proved to be useful in detecting gastro-enteropancreatic tumours; however, the role of abdominal single photon emission computed tomography has not yet been definitively established. In a series of 52 patients with gastro-enteropancreatic tumours (9 non-functioning islet cell carcinomas, 4 insulinomas, 3 somatostatinomas, 2 VIPomas, 1 glucagonoma and 33 carcinoids) we compared somatostatin receptor scintigraphy with the results of computed tomography and magnetic resonance imaging performed within one month. Four and 24-hour total body planar images and 4-hour abdominal single photon emission computed tomography were acquired after the i.v. injection of approximately 250 MBq of In-111 pentatreotide. Only abdominal localizations were considered: planar scans detected 16 extrahepatic lesions in 13 patients and 54 liver sites in 21 patients; single photon emission computed tomography visualized 31 extrahepatic lesions and 89 liver metastases in 27 and 28 patients, respectively; computed tomography and magnetic resonance imaging detected 11 extrahepatic lesions in 10 patients and 73 liver sites in 21 patients. In-111 pentatreotide single photon emission computed tomography was the only imaging method able to localize tumoural lesions in 13 patients; all these localizations were then histologically verified. The scintigraphic positivity did not depend on the site or on the presence of hormonal hypersecretions. In conclusion, our results indicate that single photon emission computed tomography is more sensitive than planar images and computed tomography/magnetic resonance imaging in detecting abdominal gastro-enteropancreatic tumours and their metastases; it is able to increase both the number of visualized lesions and that of patients with positive findings. Single photon emission computed tomography is particularly useful in patients in whom tumoural lesions have not been already localized; it should be the first imaging modality in patients with gastro-enteropancreatic tumours: its initial use will result in more information and proper management.
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PMID:Single photon emission computed tomography procedure improves accuracy of somatostatin receptor scintigraphy in gastro-entero pancreatic tumours. 1060 27


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