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)

Portal hypertension (PHT) is common in children and a majority of cases in India are constituted by extrahepatic portal venous obstruction or cirrhosis of liver. Morbidity and mortality in this condition is related to variceal bleeding, most commonly from esophageal varices. Acute variceal bleeding is best controlled by endoscopic therapy. Somatostatin and octreotide are useful in acute variceal bleeding as a supplementary therapy. Acute variceal bleeding uncontrolled by medical therapy merits preferably a shunt surgery or devascularization depending upon etiology of PHT and expertise of the surgeon. Acute variceal bleeding originating from gastric varices can be effectively controlled by endoscopic injection of tissue adhesive agent (n-butyl 2 cyanoacrylate). Eradication of esophageal varices by endoscopic measures (sclerotherapy or band ligation) is successful in prevention of recurrence of bleeding. Surgical portosystemic shunts especially in non-cirrhotic PHT are successful in achieving portal decompression and significant reduction in recurrence of variceal bleeding. Role of beta-blockers in primary prophylaxis of variceal bleeding in children still remains to be substantiated.
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PMID:Management of portal hypertension. 1242 Sep 15

Mortality due to variceal bleeding secondary to portal hypertension has decreased significantly in the past 2 decades. Endoscopic therapy has been the mainstay of treatment for acute variceal bleeding. Variceal banding ligation has superceded injection sclerotherapy as the most popular treatment modality for acute bleeding. Multiple banding ligators are widely used with high success in restoring hemostasis. The combination of banding and sclerotherapy may be useful in preventing the early recurrence of varices and rebleeding after initial obliteration of varices. Selective vasoactive agents such as somatostatin analogs also improve the outcome of patients. Radiologic shunting has proven to be an effective salvage procedure when endoscopic treatments fail and may be a good intermediate-stage therapy while the patient is waiting for liver transplantation.
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PMID:Treatment of Variceal Bleeding. 1262 76

The aim of this study was to assess the hemodynamic effects of acute and chronic administration of vapreotide, a somatostatin analog, in rats with intrahepatic portal hypertension induced by dimethylnitrosamine (DMNA) administration. Acute effects were evaluated at baseline and 30 min after placebo (N = 13) or vapreotide (8 /microg/kg/hr, N = 13) infusions in DMNA rats. Chronic hemodynamic effects were evaluated using subcutaneous implants for five weeks in anesthetized DMNA rats (placebo: N = 13, vapreotide: N = 13) and in sham rats (placebo: N = 10, vapreotide: N = 10). Hemodynamic measurements included splenorenal shunt blood flow (SRS BF) by the transit time ultrasound (TTU) method and cardiac output by the combined dilution-TTU method. Acute administration of vapreotide significantly decreased SRS BF (-17.3 +/- 19 vs - 1.1 +/- 14%, P < 0.05) and portal pressure (-8 +/- 9 vs 0 +/- 8%, p < 0.05) compared to placebo without systemic effects. Chronic administration of vapreotide significantly reduced the increase in SRS BF (2.4 +/- 1.5 vs 1.2 +/- 1.0 ml/min, P < 0.05) and cardiac index (50 +/- 15 vs 33 +/- 10 ml/min/100 g, P < 0.0001) while portal pressure and blood flow, and mean arterial pressure were not significantly changed compared to placebo. In conclusion, the acute administration of vapreotide decreased collateral circulation blood flow while chronic administration attenuated its development. Vapreotide seems to have a vasoconstrictive effect on collateral circulation.
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PMID:Hemodynamic effects of acute and chronic administration of vapreotide in rats with cirrhosis. 1264 3

The author presents a list of preparations used to influence portal hypertension resulting from cirrhosis of the liver, in particular in treatment or prevention of haemorrhage from oesophageal varices or gastropathy. The author describes the mechanism of action of drugs administered in acute haemorrhage (vasopressin, terlipressin, somatostatin, octreotide)) and preparations used in primary or secondary prevention of this haemorrhage (beta-blockers, nitrates, newly tested preparations or combinations). In the conclusion are recommendations for practical procedures according to principles of evidence-based medicine.
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PMID:[Drug therapy of portal hypertension]. 1279 61

Time-course studies revealed the increased susceptibility of the gastric mucosa to noxious injury in portal hypertension correlates with the level of elevated portal venous pressure and hyperglucagonemia. Whether acute elevation of portal venous pressure by exogenous glucagon aggravates such injury is not known. We tested the hypothesis that glucagon in a dose sufficient to acutely elevate portal venous pressure aggravates noxious injury of the gastric mucosa in rats with portal hypertension. Infusion of a portal hypotensive dose of somatostatin should reverse these changes. In anesthetized rats with portal vein ligation, glucagon, somatostatin or the combination was administered intravenously in a randomized, coded fashion. Acidified ethanol-induced gastric mucosal injury was determined. Portal venous pressure and gastric mucosal perfusion and oxygenation (reflectance spectrophotometry) were monitored to confirm the effects of the respective intravenous treatments. Exogenous glucagon exacerbated acidified ethanol-induced gastric mucosal injury. The exacerbation was attenuated by somatostatin. These changes paralleled the portal hypertensive and hypotensive effects of glucagon and somatostatin, respectively. Our data suggest that a unique mechanism is triggered with the onset of portal hypertension. In an antagonistic manner, glucagon and somatostatin modulate this novel mechanism that controls portal venous pressure and susceptibility of the gastric mucosa to noxious injury.
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PMID:Role of acute elevation of portal venous pressure by exogenous glucagon on gastric mucosal injury in rats with portal hypertension. 1281 20

Somatostatin and its analogue octreotide have been used for two decades to treat oesophageal variceal haemorrhage. The drug was introduced because of its capacity to decrease portal venous pressure without major side effects. In clinical trials assessing the efficacy of somatostatin and long-acting analogues in arresting variceal haemorrhage, conflicting results have been obtained. Furthermore, in haemodynamic studies evaluating the effects of somatostatin and analogues in patients with cirrhosis, divergent effects were observed. The main reason for these differences is probably related to different affinities of the drugs for different somatostatin receptor subtypes. The effects of somatostatin and analogues are mediated via five different G-protein coupled receptors (somatostatin receptor subtypes 1-5), which regulate the activity of ion channels (Ca2+, K+, Na+ and Cl-) and enzymes (adenyl cyclase, phospholipase C, phospholipase A2, phosphoinositide 3-kinase and guanylate cyclase) responsible for the synthesis or degradation of intracellular second messengers including cyclic AMP, inositol 1,4,5-trisphosphate, diacylglycerol and cyclic GMP. Despite universal use of somatostatin, the cellular and biochemical mechanisms of its effects in portal hypertension are relatively poorly studied and remain incompletely understood. In this review, we summarize relevant signal transduction of somatostatin and analogues, the haemodynamic effects of the drugs and the possible mechanisms by which these effects are mediated.
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PMID:Pharmacological rationale for the use of somatostatin and analogues in portal hypertension. 1294 Sep 22

The incidence of hepatocellular carcinoma (HCC) is increasing in the United States. Several modalities are available for the treatment of HCC, and decisions regarding the optimal choice of therapy are based on tumor burden and severity of liver disease. Classification systems are helpful for prognostic purposes and to guide in the choice of therapy. Surgical resection is a mainstay of therapy for patients with solitary small tumors and preserved liver function (noncirrhotic or Child-Pugh class A cirrhotic patients without portal hypertension). Unfortunately, a minority of patients is eligible for resection, and postoperative recurrence or de novo HCC is common. Liver transplantation offers the best chance of curing HCC in cirrhotic patients. Patients with a solitary tumor less than 5 cm or no more than three tumors each 3 cm or less have a survival rate of 70% with less than 20% recurrence at 5 years. Access to liver transplantation is limited by organ availability, and tumor progression during the waiting period can lead to ineligibility. Ethanol injection and radiofrequency ablation are effective modalities to ablate small tumors (generally <5 cm) in patients who are not candidates for resection or liver transplantation. These modalities can also be used to treat HCC prior to liver transplantation. Transarterial chemoembolization is used to treat patients with multifocal or large HCC who are ineligible for other therapies. Chemotherapeutic agents are infused into the tumor via the hepatic artery along with embolic material in order to induce tumor necrosis. This technique should be used in selective patients with relatively preserved liver function, absence of portal vein thrombosis, or encephalopathy. Limited data exist to support the use of this modality as a primary treatment option for small HCC. Chemotherapeutic or hormonal therapies have a limited role in the management of patients with HCC. Despite mixed outcomes, we routinely use the somatostatin analog octreotide in advanced, multifocal HCC. Emerging therapies should focus on treatment of small tumors and targeted pharmacologic therapy for advanced disease.
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PMID:Treatment of Hepatocellular Carcinoma. 1458 35

Portal hypertension bleeding is a common and serious complication of cirrhosis. All patients with cirrhosis should undergo endoscopy and be evaluated for possible causes of current or future portal hypertensive bleeding. Possible causes of bleeding include esophageal varices, gastric varices, and PHG. Patients with esophageal varices at high risk of bleeding should be treated with nonselective beta-blockers for primary prevention of variceal hemorrhage. HVPG measurements represent the optimal way to monitor the success of pharmacologic therapy. EVL may be used in those with high-risk varices who do not tolerate beta-blockers. When active bleeding develops, simultaneous and coordinated attention must be given to hemodynamic resuscitation, prevention and treatment of complications, and active control of bleeding. In cases of acute esophageal variceal (Fig. 5) and PHG bleeding, terlipressin, somatostatin, or octreotide should be started. Endoscopic treatment is provided for those with bleeding esophageal varices. If first-line therapy fails, TIPS or surgery may need to be performed. Unlike esophageal variceal or PHG bleeding, there is no established optimal treatment for gastric variceal bleeding. Individual and specific treatment modalities for acute gastric variceal bleeding must be calculated carefully after considering side effects.
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PMID:Portal hypertensive bleeding. 1469 98

Somatostatin is produced in enteroendocrine D cells and intrinsic neurons of the stomach, intestines and pancreas. Its physiologic actions are mediated primarily by somatostatin receptors type 2 and 5, and include the inhibition of secretion of most endocrine and exocrine factors. Diseases directly attributable to somatostatin excess or deficiency are rare, although there is a complex pathogenic relationship between persistent Helicobacter pylori infection and reduced somatostatin in chronic gastritis. Abundant somatostatin receptors on many neoplastic and inflammatory cells are the basis for sensitive in vivo imaging with radiolabeled somatostatin analogs and provide a therapeutic target. Current indications for somatostatin therapy include hormone-expressing neuroendocrine tumors, intractable diarrhea and variceal bleeding secondary to portal hypertension. Exciting advances are being made in the development of high-affinity nonpeptide analogs with receptor-subtype selectivity and increased bioavailability. Somatostatin analogs coupled to high-energy radionuclides show promise as novel cytotoxic agents for certain metastatic tumors.
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PMID:Clinical endocrinology and metabolism. The somatostatin neuroendocrine system: physiology and clinical relevance in gastrointestinal and pancreatic disorders. 1553 78

Treatment of portal hypertension is evolving based on randomised controlled trials. In acute variceal bleeding, prophylactic antibiotics are mandatory, reducing mortality as well as preventing infections. Terlipressin or somatostatin combined with endoscopic ligation or sclerotherapy is the best strategy for control of bleeding but there is no added effect of vasoactive drugs on mortality. Non-selective beta-blockers are the first choice therapy for both secondary and primary prevention; if contraindications or intolerance to beta-blockers are present then band ligation should be used. Novel therapies target the increased intrahepatic resistance caused by microcirculatory intrahepatic deficiency of nitric oxide and contraction of activated intrahepatic stellate cells.
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PMID:Management of portal hypertension. 1553 46


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