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)

We investigated the effect of endothelin-1 on relaxation responses induced by vasodilator substances in canine middle cerebral arteries to better understand regulation of cerebrovascular tone and its potential impact on mechanism of cerebral vasospasm. Endothelin-1 elicited concentration-dependent contractions in helical strips of canine cerebral arteries (EC50; 4.62 x 10(-9) M). Pretreatment with 10(-9) M endothelin-1 significantly reduced endothelium-dependent relaxation elicited by substance P and endothelium-independent relaxations by nitroglycerin, prostaglandin I2, and KCl. Although endothelin-1 in a lower concentration (10(-10) M) did not affect these endothelium-independent relaxations, it did inhibit endothelium-dependent relaxation caused by substance P. A low concentration (10(-10) M) of endothelin-1 also significantly reduced endothelium-dependent relaxation of canine mesenteric arteries induced by acetylcholine. Other vasoconstrictor peptides such as angiotensin-II and vasopressin did not inhibit endothelium-dependent and -independent relaxations. These results indicate that endothelin-1 not only produces cerebral vasoconstriction but also interferes with vasodilator mechanisms and that endothelium-dependent vasodilation is more sensitive to the inhibitory effect of endothelin-1 than endothelium-independent vasodiltion.
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PMID:Suppression of cerebral vasodilation with endothelin-1. 853 97

We have recently developed a noninvasive dimethylether (DME) uptake technique to estimate airway mucosal blood flow (Qaw) in humans (12). Because it was not feasible to validate the technique directly, we undertook the present study to compare Qaw as measured by DME (QDME) and by color-coded microspheres (QM) as a standard in seven anesthetized sheep prepared with a carotid and a left atrial catheter. QDME was determined by measuring DME uptake with multiple breath holds after passive inflation with a DME-helium gas mixture, simulating the technique used in humans. After the microspheres were injected into the left atrium, the sheep were killed and the tracheal segment corresponding to the dead space from which DME uptake was determined was removed, and its mucosa was stripped and processed for microsphere counts. Mean QDME was 35.6 ml.min-1.100 g-1 wet tissue (range 9.6-98.0 ml.min-1.100 g-1) and mean QM was 29.1 ml.min-1.100 g-1 (range 7.7-91.5 ml.min-1.100 g-1). There was a strong correlation between QDME and QM (r = 0.89; P = 0.01). Intravenous nitroglycerin and vasopressin caused comparable increases and/or decreases in QDME and QM (r = 0.87; P = 0.02). This suggests that the noninvasive DME uptake method measures Qaw accurately and supports its validity in human studies.
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PMID:Measurement of airway mucosal blood flow with dimethylether: validation with microspheres. 856 87

In this study, we carried out an immunohistochemical evaluation of the neurochemical characteristics of neurons that are activated (i.e., express Fos protein) in response to systemic administration of nitroglycerin. In the brain stem, a significant percentage of activated neurons contained noradrenaline as a neurotransmitter, whereas only a few of them contained serotonin. In the paraventricular and supraoptic nuclei of the hypothalamus, numerous Fos-immunoreactive neurons were also positive for vasopressin, oxytocin, and corticotropin-releasing factor. Codistribution with corticotropin-releasing factor was also observed in the central nucleus of the amygdala. Our findings point out a prominent role for catecholaminergic and peptidergic pathways in the brain in response to systemic nitroglycerin.
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PMID:Systemic nitroglycerin activates peptidergic and catecholaminergic pathways in rat brain. 873 71

Nitric oxide (NO) reduces blood pressure in vivo by two mechanisms, vasodilation and increasing urinary volume: however, the exact mechanism by which it increases urinary volume is not clear. We hypothesized that NO inhibits antidiuretic hormone (ADH)-stimulated fluid reabsorption (J(r)) by the isolated rat cortical collecting duct (CCD) by decreasing water permeability (Pf) and sodium reabsorption (Jna). In the presence of 10(-11) MADH, Jv was 0.15 +/- 0.04 nl.min-1.mm-1; after 10(-6) M spermine nonoate (SPM) was added to the bath. Jv decreased to 0.06 +/- 0.03 nl.min-1.mm-1 (P < 0.03). To investigate whether the inhibition of Jv was the result of decreased Pf and/or Jna, we first tested the effect of SPM on ADH-stimulated Pf. Basal Pf was stimulated to 289.2 +/- 77.3 microns/s after 10(-11) M ADH was added to the bath (P < 0.01). SPM decreased Pf to 159.8 +/- 45.0 microns/s (P < 0.05). To ensure that this effect on Pf was due to NO release, we used another NO donor, nitroglycerin (NTG). Pf was initially -25.8 +/- 18.3 microns/s and increased to 133.9 +/- 30.5 microns/s after addition of 10(-11) M ADH (P < 0.002). NTG, 20 microM, lowered Pf to 92.4 +/- 18.4 microns/s (P < 0.02). In the presence of 10(-9) M ADH, NTG also decreased Pf(P < 0.04). Next we investigated the effect of SPM on ADH-stimulated JNa. In the presence of ADH, JNa was 37.8 +/- 7.3 pmol.min-1.mm-1. After SPM was added, it dropped to 24.3 +/- 5.1 pmol.min-1.mm-1 (P < 0.05). Time controls exhibited no change in ADH-stimulated Jv, Pf, or Jna. We concluded that 1) NO decreases ADH-stimulated water and sodium transport in the isolate CCD, and 2) water reabsorption is inhibited by a primary effect on Pf. A direct effect of NO on the CCD may explain its natriuretic and diuretic effects observed in vivo.
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PMID:Nitric oxide inhibits ADH-stimulated osmotic water permeability in cortical collecting ducts. 876 41

The available pharmacological treatments for portal hypertension are reviewed. Vasoconstrictor treatments include vasopressin (VP), the synthetic VP analogue tGLVP, combined nitroglycerin (NTG)-VP, somatostatin (SRIF), SRIF analogues and non-selective beta-blockers. Vasodilator treatments include short- and long-acting organic nitrates. Infusions of VP > 1.0 U/min can cause severe side-effects. tGLVP can control variceal bleeding and improve survival and causes fewer complications than VP.SRIF is as effective as tGLVP in controlling bleeding and improving survival and has minimal side effects. Beta-blockers are effective in preventing the first variceal haemorrhage and are well tolerated.
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PMID:Pharmacological treatment of portal hypertension. 881 85

Acute bleeding due to esophageal varices continues to be a life-threatening complication of liver disease. Despite the availability of improved therapy, mortality continues to be high. Octreotide has been shown to be at least as effective as vasopressin in the treatment of bleeding varices, with fewer and less severe systemic adverse effects. In addition, octreotide has also been consistently associated with a decreased need for transfusions. Octreotide has been used safely in patients without serious cardiovascular disease when administered as a continuous intravenous infusion of 25 micrograms/h for 24 hours with or without an initial 100-micrograms bolus dose. Since these trials have used small numbers of patients, the ability to detect small but clinically important differences has been limited. Additional controlled trials comparing octreotide with the combination of vasopressin and nitroglycerin are needed to more clearly determine the efficacy and cost-effectiveness of therapy. Furthermore, the optimal dosage, duration, and route of administration of octreotide in the treatment of bleeding esophageal varices has yet to be determined.
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PMID:Octreotide or vasopressin for bleeding esophageal varices. 903 26

Bleeding from esophageal varices presents a considerable challenge to clinicians. Adequate fluid resuscitation must be undertaken before urgent endoscopy. Pharmacotherapy of acute variceal hemorrhage consists of either vasopressin plus nitroglycerin or intravenous octreotide. Vasopressin should not be used alone because of a high incidence of side effects such as cardiac and/or visceral ischemia. Band ligation appears superior to sclerotherapy primarily because of decreased rebleeding from varices and decreased esophageal stricture formation among patients undergoing band ligation. Future trials with newer sclerosant agents, such as cyanoacrylate, are anxiously awaited.
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PMID:Endoscopic management of esophageal variceal hemorrhage: injection, banding, glue, octreotide, or a combination? 936 Feb 82

The anti-ischemic effects of organic nitrates are rapidly attenuated due to the development of nitrate tolerance. The mechanisms underlying this phenomenon likely involve several independent factors. As a vasodilator, nitroglycerin activates compensatory neurohumoral mechanisms such as the renin-angiotensin system and increases catecholamine and vasopressin levels, all of which may attenuate its vasodilator potency. Tolerance may be also due to the inability of the vessel to dilate after prolonged treatment with the nitrate. More recent experimental studies have challenged traditional tolerance concepts by demonstrating that tolerance is not associated with sulfhydryl group depletion, reduced nitroglycerin biotransformation, or desensitization of the target enzyme guanylyl-cyclase. Experimental and clinical observations suggest that tolerance may be the consequence of intrinsic abnormalities of the vasculature, including enhanced endothelial production of oxygen-derived free radicals secondary to an activation of NAD(P)H-dependent oxidases and an activation of PKC. Superoxide degrades nitric oxide derived from nitroglycerin (NTG) while C activation causes enhanced sensitivity of the vasculature to circulating neurohormones such as catecholamines, angiotensin II, and serotonin, all of which may compromise the vasodilator potency of NTG. Interestingly, these vascular consequences of in vivo NTG treatment such as superoxide production and PKC activation can be mimicked in vitro by incubating cultured endothelial and smooth muscle cells with angiotensin II. Furthermore, nitrate tolerance and rebound following sudden cessation of prolonged NTG therapy can be prevented by concomitant treatment with high-dose angiotensin-converting enzyme inhibition, angiotensin type 1 receptor blockade, or antioxidants such as hydralazine. Thus one can conclude that neurohumoral counterregulatory mechanisms such as increased circulating levels of angiotensin II may be at least in part responsible for tolerance mechanisms at the cellular level.
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PMID:Evidence for a role of oxygen-derived free radicals and protein kinase C in nitrate tolerance. 942 22

Although vasopressin increases vital organ blood flow during cardiopulmonary resuscitation (CPR), endocardial perfusion remains suboptimal. This study was designed to assess the effects of vasopressin versus a combination of vasopressin and nitroglycerin on vital organ blood flow in a porcine model of CPR. After 4 min of cardiac arrest, and 3 min of closed-chest compressions, 14 animals were randomly treated with either 0.4 U/kg vasopressin (n = 7) or 0.4 U/kg vasopressin combined with 5 microg/kg nitroglycerin (n = 7). Coronary and cerebral perfusion pressure as well as left ventricular myocardial blood flow was comparable between groups throughout the experiment. Ninety seconds after drug administration, vasopressin combined with nitroglycerin resulted in comparison with vasopressin alone in significantly higher mean (+/- standard error of the mean) left ventricular endocardial blood flow (78+/-7 vs 51+/-5 ml x min(-1) x 100 g(-1); P < 0.05), and a significantly higher endocardial/epicardial perfusion ratio (0.93+/-0.09 vs 0.57+/-0.06; P < 0.05). Seven of seven animals in the vasopressin group, and four of seven animals in the vasopressin and nitroglycerin group (NS) were resuscitated successfully and survived the 2-h observation period. We conclude that, when compared with vasopressin therapy alone, combined vasopressin and nitroglycerin improved endocardial perfusion significantly immediately after drug administration during CPR.
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PMID:Vasopressin combined with nitroglycerin increases endocardial perfusion during cardiopulmonary resuscitation in pigs. 978 4

Pharmacologic therapy used during acute variceal bleeding may control the bleeding episode, minimized transfusion requirements, and prevent early rebleeding. Several options for pharmacologic therapy exist in this setting and include: vasopressin in combination with nitroglycerin, terlipressin, somatostatin, and octreotide. Metoclopramide and domperidone may also be useful but require additional study. At present, octreotide, administered intravenously as soon as variceal bleeding is suspected, is favored.
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PMID:Pharmacological prevention of rebleeding. 1033 44


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