Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01185 (vasopressin)
 23,126 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Our previous studies have shown that stimulation of the anteroventral third ventricle region increases atrial natriuretic peptide (ANP) release, whereas lesions of the anteroventral third ventricle or median eminence block the release of ANP from blood volume expansion, suggesting a critical central nervous system participation in this response. ANP is also produced within neurons that have cell bodies in the rostral hypothalamus and axons that extend to the median eminence and neural lobe. In addition to its natriuretic effect, the peptide can inhibit the release of corticotropin (ACTH) and prolactin, anterior pituitary hormones that are released during stress. To determine the physiologic significance of ANP in the control of basal and stress-induced release of anterior pituitary hormones, highly specific antiserum against the peptide (AB-ANP) was microinjected into the third cerebral ventricle of conscious freely moving male rats to immunoneutralize hypothalamic ANP. In the initial experiment, the antiserum or control normal rabbit serum (NRS) was injected into the third cerebral ventricle to determine the effect of the antiserum on basal release of pituitary hormones. The antiserum had no effect on the concentrations of plasma ACTH, prolactin, or thyroid-stimulating hormone for 3 hr after the injection; however, plasma growth hormone concentration, although unchanged for 2 hr, was markedly elevated at 3 hr. These results indicate that although ANP appears to have no effect on the basal release of the other hormones, it has a physiologically significant inhibitory effect on growth hormone release. The delay of the effect is probably related to the time required for the antiserum to diffuse to the site of action of the peptide, presumably at some distance from the ventricle. Since this effect was demonstrable only after 3 hr, in the stress experiment, the antiserum or NRS was microinjected into the third ventricle 3 hr prior to application of ether stress. The rapid elevation of plasma ACTH in NRS-injected rats was markedly augmented by AB-ANP. Ether also induced a rapid increase in plasma prolactin in the NRS-injected animals, as expected. Contrary to the ACTH response, the maximal increase in plasma prolactin after ether was attenuated in animals preinjected with AB-ANP. In the NRS-injected animals, there was a significant decline in plasma growth hormone after the application of ether that was significantly accentuated by AB-ANP, but this was probably the result of the higher initial levels of plasma growth hormone in the ANP-AB group followed by its disappearance with a half-time similar to that of the NRS-injected group. The decline in plasma thyroid-stimulating hormone after ether stress was unaltered in the animals injected with AB-ANP. The results of these immunoneutralization studies suggest that endogenous ANP does not play a role in thyroid-stimulating hormone release. On the other hand, the endogenous peptide appears to have a physiologically significant inhibitory role in suppressing ACTH release during stress, mediated at least partly by suppression of vasopressin release. Endogenous ANP has a pathophysiologic role in augmenting the prolactin release in stress either by inhibiting release of prolactin-inhibiting factors or, alternatively, by enhancing release of prolactin-releasing factors. Endogenous ANP appears to inhibit resting, without altering stress-induced inhibition of growth hormone release by stimulating somatostatin release and/or inhibiting growth hormone-releasing hormone release or by both actions.
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PMID:The role of endogenous atrial natriuretic peptide in resting and stress-induced release of corticotropin, prolactin, growth hormone, and thyroid-stimulating hormone. 133 8

The effects of arginine-vasopressin (AVP) on hormone release by the endocrine pancreas have been studied with incubated islets from normal mice. A wide range of AVP concentrations (1 pM-100 nM) were tested in the presence of various glucose concentrations. AVP did not affect somatostatin release in a glucose-free medium but increased it in the presence of all tested glucose concentrations (3-30 mM). The lowest effective concentration was 1 mM and the effect was not yet maximal at 100 nM AVP. AVP markedly increased glucagon release in the absence of glucose. Its effect was attenuated but not abolished when glucagon release was inhibited by glucose. Surprisingly, the attenuation of the effect of AVP was stronger in 3-10 mM than in 15-30 mM glucose. The lowest effective concentration was 1 nM and the effect was not yet maximal at 100 nM AVP. AVP was ineffective on basal insulin release (0, 3 and 7 mM glucose), but potentiated the effect of 10, 15 and 30 mM glucose. The lowest effective concentration was 0.1-1 nM AVP and the maximal effect was produced by 10-100 nM AVP. The results suggest a direct action of AVP on each of the three islet cell types which display a roughly similar sensitivity to the peptide. This sensitivity is too low to make islet cells a possible target for circulating AVP under physiological conditions. On the other hand, the presence of AVP in the pancreas suggests that it might be involved in the peptidergic control of islet function.
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PMID:Glucose- and concentration-dependence of vasopressin-induced hormone release by mouse pancreatic islets. 134 42

The effects of a single intraperitoneal injection of ethanol (3 g/kg b.wt.) on the hypothalamic-pituitary-thyroid system was explored as a possible explanation of the hypothermic effect of ethanol. Serum thyroid hormones were significantly reduced by ethanol injection, but ethanol did not affect the cold-induced increase in serum thyroid hormones or thyroid-stimulating hormone (TSH). Since cold-exposure stimulates serum levels of TSH and thyroid hormones by stimulating thyroid-releasing hormone (TRH) release from neurons of the PVN, these findings demonstrate that ethanol did not block pituitary response to TRH or thyroid response to TSH. Paradoxically, ethanol increased cellular levels of TRH mRNA in the paraventricular nucleus (PVN), and blocked the cold-induced increase in TRH mRNA, suggesting that ethanol uncouples the regulation of TRH gene expression from the regulation of TRH release specifically in neurons of the PVN. Measurements of the effects of ethanol on TRH mRNA in thalamus, and beta-actin, vasopressin, somatostatin and corticotropin-releasing hormone (CRH) mRNAs in the PVN in addition to TRH mRNA revealed very specific effects of ethanol on the TRH neuronal system.
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PMID:Ethanol blocks the cold-induced increase in thyrotropin-releasing hormone mRNA in paraventricular nuclei but not the cold-induced increase in thyrotropin. 135 12

Successful pharmacological arrest of haemorrhage might avoid the risk of aspiration associated with tamponade and early studies have suggested that the vasoactive agent somatostatin may be as effective and perhaps safer than tamponade in controlling variceal haemorrhage. In our view, vasopressin has not established a role in management but we retain an open mind regarding the potential use of terlipressin in combination with nitroglycerin. It is unlikely that any of these agents can improve significantly our ability to control variceal haemorrhage when compared to balloon tamponade but they may reduce the incidence of pulmonary complications and thereby reduce subsequent mortality. Tamponade has proved successful in controlling acute haemorrhage from oesophageal varices in our hands. Late complications continue to give cause for concern but until effective safe alternatives to tamponade are developed, we continue to advocate its use for emergency control of acute variceal haemorrhage. Our own studies have shown that the high mortality seen in this patient population may reflect the severity of the underlying liver disease rather than failure of a management policy employing oesophageal tamponade for the initial control of acute variceal haemorrhage.
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PMID:Balloon tamponade and vasoactive drugs in the control of acute variceal haemorrhage. 135 76

To investigate the renal effects of somatostatin in cirrhosis, renal function and plasma and urinary levels of endogenous neurohumoral vasoactive substances were measured in conditions of intravenous water overload (20 mL/kg body wt with 5% glucose) before and during the intravenous infusion of somatostatin (250-500 micrograms/h) in 6 cirrhotic patients without ascites and 17 nonazotemic cirrhotic patients with ascites. Somatostatin induced a significant reduction of renal plasma flow, glomerular filtration rate, and free water clearance in both groups of patients. In patients with ascites, somatostatin also reduced urinary sodium excretion. Changes in renal function were significantly more marked in patients with ascites than in those without ascites and occurred in the absence of changes in mean arterial pressure and plasma levels of renin, aldosterone, norepinephrine, antidiuretic hormone, and atrial natriuretic peptide. Somatostatin induced a significant reduction in the plasma concentration of glucagon and urinary excretion of prostaglandin E2 that was not related to changes in renal function. These findings indicate that somatostatin administration induces renal vasoconstriction and impairs glomerular filtration rate, free water clearance, and sodium excretion in cirrhosis by a mechanism unrelated to systemic hemodynamics and endogenous neurohumoral vasoactive systems.
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PMID:Effects of somatostatin on renal function in cirrhosis. 809 52

1) Emergency treatment. The best treatment remains endoscopic sclerotherapy, which controls the bleeding in 90% of the cases. Pharmacologic management stops the variceal hemorrhage in 80% of the cases and is indicated before endoscopic treatment can be performed. Intravenous somatostatin administration may be prolonged for 5 days, even more, and may thus prevent early rebleeding, which is not achieved neither by vasopressin nor by glypressin, which administration is restricted to 24 hours. Esophageal tamponade is useful to arrest a massive variceal bleeding, if vasoactive drugs are not available or not efficient, before endoscopic management. If the bleeding persists after 2 sclerotherapy sessions, an alternative treatment is mandatory: the patient should be sent to the surgeon for a portosystemic shunt if the operative risk is acceptable (child A and B) or should become a candidate for a transjugular intrahepatic stent shunt, especially if transplantation is considered afterwards. 2) Prevention of recurrent hemorrhage. A) Early (within 5 days after the initial bleeding). Somatostatin probably prevents early rebleeding, as do sclerotherapy. B) Late. B blockade (+ nitrates) or long-term sclerotherapy have the same efficacy. Their association may improve their results. 3) Prevention of the first bleeding episode. Propranolol decrease the risk of variceal rupture from 20% to 9% during the first year after the diagnosis of esophageal varices and is the only treatment which may be proposed to cirrhotics who did not yet bled form their varices.
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PMID:[Prevention and treatment of digestive hemorrhage due to ruptured esophageal varices in patients with cirrhosis]. 136 Oct 90

1. Using an immunocytochemical procedure a wide range of immunoreactive vertebrate bioactive peptides (BAPs) has been found in hemocytes of Viviparus ater: bombesin, calcitonin, CCK-8, CCK-39, GH, glucagon, insulin, oxytocin, neurotensin, secretin, serotonin, somatostatin, substance P, vasopressin, and VIP. 2. No immunostaining was observed for antigastrin and antithyroglobulin antibodies. 3. The presence of BAP-like molecules in hemocytes suggests a correlation between hemocyte and APUD cells and is evidence of a relationship between the neuroendocrine and the immune systems.
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PMID:The presence of immunoreactive vertebrate bioactive peptide substances in hemocytes of the freshwater snail Viviparus ater (Gastropoda, Prosobranchia). 136 24

Although the mechanism initiating and maintaining variceal hemorrhage is not completely understood, there has been general agreement in recent years on the concept that variceal rupture occurs when the tension on the wall of the varices reaches a critical value (the rupture point) that leads to the leakage of the elastic components of the wall. If this hypothesis is true, the aim of pharmacological treatment should be to reduce variceal wall tension or to prevent any abrupt increase in this parameter. Some vasoconstrictor drugs are currently used in order to achieve these goals and in the attempt to stop the acute bleeding episode. All these agents decrease either portal pressure and azygos blood flow. Vasopressin although effective, has significant cardiac and gastrointestinal adverse effects that discourage its use. Combination with nitroglycerin reduces its adverse effects while maintaining or even enhancing the reduction in portal pressure. Glypressin, which acts as a slow-release preparation of vasopressin, has a longer duration of action and can be administered as single intravenous injections instead of continuous infusion. However, the similarity of effects of these drugs on systemic circulation leads to an overlapping spectrum of untoward effects. Somatostatin and the synthetic octapeptide octreotide display similar pharmacological effects on splanchnic hemodynamics but have a better tolerability profile. Thanks to its longer duration of action and ease of administration, octreotide could become the drug of choice for the early, pre-hospital management of bleeding varices. A different approach to the pharmacological treatment of variceal bleeding may be the use of compounds, like metoclopramide and domperidone, that increase the lower esophageal sphincter pressure (LESP), thereby reducing the inflow of blood flow into the submucous venous plexus of the esophagus and hence into the esophageal varices. However, more studies are needed before these compounds be considered a real alternative to the above established drugs.
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PMID:Clinical pharmacology of active variceal bleeding. 136 76

Vasoactive drug therapy is the only therapy that can be administered immediately to patients with suspected variceal bleeding. The optimal agent is not yet available, but somatostatin or octreotide, glypressin and vasopressin and nitroglycerin are the best candidates. Somatostatin and octreotide have the best therapeutic index as they have very few side effects. They compare well to the other agents in comparative randomized trials. In addition to being used prior to sclerotherapy, vasoactive agents may show benefit when used in combination with endoscopic methods and in the immediate interval thereafter in order to prevent early re-bleeding. This remains to be tested in clinical trials.
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PMID:Medical management of bleeding esophageal varices. 136 77

Variceal bleeding is the most important complication of portal hypertension. Mortality due to the first variceal bleeding is very high (50%) and of those surviving a variceal bleeding episode, up to 80% may rebleed. Proper management of the acute variceal bleeding episode, the prevention of rebleeding and primary prophylaxis for variceal haemorrhage are therefore mandatory in order to improve the morbidity and mortality of cirrhotic patients with variceal bleeding. Injection sclerotherapy would be the treatment of choice for acute variceal bleeding. Drug treatment in the form of either a combined vasopressin-nitroglycerin regimen or somatostatin may be used as an alternative. Patients not responding to these treatments should be referred for surgery. For the prevention of variceal rebleeding, non-selective beta-blockers should be tried first, reserving long-term injection sclerotherapy for patients with contraindications or intolerance to beta-blockers or in whom beta-blocker therapy has failed. Surgical rescue in the form of either shunt surgery or lever transplantation should be considered if either treatment fails. A new technique, transjugular intrahepatic portosystemic stent-shunt (TIPSS) may replace shunt surgery in the future. Beta-blockers is the treatment of choice for primary prophylaxis of variceal haemorrhage and has a role in preventing acute and chronic bleeding from congestive gastropathy. However, the above sequential approach from the least invasive to the more invasive therapeutic options may not be appropriate for all cirrhotic patients with variceal bleeding.
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PMID:Management of variceal haemorrhage. 136 89


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