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)

1. Isoelectric focusing studies of human placental diamine oxidase showed the pI value of the active enzyme to be 6.5. This information was used in modifying the enzyme purification by incorporating column chromatography on DEAE-Sephadex with ionic strength and pH gradient elution and this, together with affinity chromatography on concanavalin A--Sepharose, gave a highly purified preparation, with a specific activity of 7.0 units/mg. 2. The enzyme gave the expected stoicheiometry with p-dimethylaminomethylbenzylamine as substrate (Keq. 2700) and also oxidized [8-arginine]vasopressin, [8-lysine]vasopressin, collagen and tropocollagen. Polyacrylamide gel slices showed identical migration of diamine-oxidizing and [8-lysine]vasopressin-oxidizing activity. 3. The molecular weight, determined by ultracentrifugation, sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, variable polyacrylamide-gel electrophoresis and Sephadex G-200 column chromatography, was estimated to be approx. 70000. 4. E.s.r. spectroscopy showed that copper and manganese were present in the purified enzyme. This result was confirmed by atomic absorption spectroscopy, which indicated a stoicheiometry for copper and manganese of approx. 1.0 and 1.2g-atom respectively/70000mol.wt. unit. 5. The e.s.r. spectral intensity did not decrease nor did the spectral line shape change when excess of p-dimethylaminomethylbenzylamine was added to the enzyme. 6. Addition of K13CN to the enzyme eliminated the copper e.s.r. signal without affecting the manganese signal. 7. The placental enzyme therefore appears to differ from other amine oxidases in terms of its metal cofactor requirement, molecular weight and substrate specificity, and possible roles in vivo for this enzyme are discussed.
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PMID:Human placental diamine oxidase. Improved purification and characterization of a copper- and manganese-containing amine oxidase with novel substrate specificity. 18 34

A fluorometric method for the quantitative assay of vasopressin and oxytocin in individual rat pituitaries has been developed. Acid extracts of pituitaries are freed of amino acids and polyamines by passage over a copper-Sephadex column, and the peptides fraction is then labeled by reaction with fluorescamine. The resulting peptide fluorophors are separated by chromatography on a reverse-phase bonded column. Specificity of the procedure was ascertained by several criteria, including bioassay and amino-acid analysis of the eluted peptide fluorophors. The procedure serves as a model system for the assay of tissue peptides in the picomole range.
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PMID:Fluorometric assay of vasopressin and oxytocin: a general approach to the assay of peptides in tissues. 106 12

The results are reported of a potentiometric and spectroscopic study of the H+ and Cu2+ complexes of Ala-Arg8-vasopressin (Ala-AVP) and oxytocin at 25 degrees C and an ionic strength of 0.10 mol dm-3 (KNO3). The coordination chemistry of oxytocin and Cu(II) has been shown to be virtually identical to that of Arg8-vasotocin, forming unusually stable complexes with four nitrogen coordination (4N complexes) below pH 7. Spectroscopic evidence suggests weak interaction between Cu(II) and the sulphur atom of the -Cys6- residue in the 2N species (pH congruent to 6) but this is absent in the 4N complex. Evidence is also presented for perturbation of electronic transitions within the aromatic ring of the Tyr residue by Cu(II). While the physiological potency of Ala-AVP is very high, its coordination chemistry differs significantly from that of Arg8-vasopressin. With Cu(II) it forms complexes of similar stability to those with tetraglycine, demonstrating that the addition of an alanyl residue to the amino-terminal of the peptide destroys the conformation which is particularly favorable for rapid 4N coordination.
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PMID:Potentiometric and spectroscopic studies of the Cu(II) complexes of Ala-Arg8-vasopressin and oxytocin: two vasopressin-like peptides. 132 87

Rapid freezing of freshly dissected or incubated neural lobes was explored as a means of obtaining ultrastructural preservation of the more natural state of this tissue. A quantitative assessment of the region of good fixation was made in order to determine the relative fractions occupied by axons, pituicytes and the extracellular space. The immunocytochemical distributions of neurophysins and the glycopeptide portion of the vasopressin precursor were evaluated using the immunogold technique in order to determine the relative numbers of oxytocin and vasopressin fibre types in the fixed region, and the subcellular localization of these antigens. The uncut surface of rat neural lobes was rapidly frozen against a highly polished copper plug and freeze-substituted in osmium-acetone either immediately after dissection (approximately 2 min), or after a 15 min incubation period in vitro in an oxygenated, balanced salt solution. Substituted neural lobes were prepared for either conventional electron microscopy, or for immunogold labelling of neurophysins and the glycopeptide precursor to vasopressin. Membranes, subcellular organelles and extracellular matrix were well preserved 10 microns deep to the contacted surface. The extracellular space accounted for approximately 30% of the cross-sectional area of the neuropil and could be divided into two domains: an extended perivascular space (28-29% of total area); and a narrow (approximately 24 nm; approximately 1% of total) space between closely apposed neurosecretory processes or between these processes and pituicytes. Pituicytes accounted for about 30% of the area and axons 20-25%. Pituicytes occupied close to 60% of the basal lamina at the neurohaemal contact zone, while axons occupied approximately 20%. There were no differences between neural lobes frozen immediately after dissection and those incubated for 15 min in any of these measures, suggesting minimal fluid redistribution. Gold particles were specifically localized over large (100-200 nm) dense core vesicles, and less frequently over multivesicular bodies and lysosomes. No etching of the plastic or reduction of osmium was necessary to achieve labelling. Specific labelling of one set of terminals and axons (about 80%) was observed with the monoclonal antibody previously shown to be specific for oxytocin-neurophysin, while in neighbouring sections the remaining 20% of the processes were labelled with the antiserum to the vasopressin precursor, or with non-specific antibodies to neurophysins. In conclusion, ultrarapid freezing preserves a large extracellular space in the neural lobe and provides for high resolution morphological and immunocytochemical studies of neurohypophysial structure.
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PMID:Electron microscopic and immunocytochemical study of rapidly frozen, freeze-substituted neural lobes of rats. 202 40

Administration of lithium chloride, copper sulfate, and apomorphine to rats each stimulated the secretion of oxytocin (OT) and, to a much lesser degree, arginine vasopressin. These agents are assumed to cause visceral illness in rats because of their effectiveness in promoting the acquisition of learned taste aversions. CuSO4 had a greater effect on plasma OT levels when administered ip rather than iv, whereas LiCl did not, results suggesting that LiCl probably stimulates OT secretion by central chemoreceptor activation whereas CuSO4 acts predominantly by local peritoneal irritation. A causal role for circulating OT in the acquisition of learned taste aversions was not found. These and other findings suggest that peripheral levels of OT may represent a quantifiable marker of visceral illness in rats and therefore might be useful in the interpretation of behavioral studies in which learned taste aversions are produced, provided that other stimuli of neurohypophyseal secretion are absent.
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PMID:Oxytocin and vasopressin secretion in response to stimuli producing learned taste aversions in rats. 301 74

Administration of lithium chloride and copper sulfate to adult monkeys caused marked elevations in plasma vasopressin (AVP) levels without significant increases in plasma oxytocin (OT) levels. Emesis was produced in five of the seven animals given these agents, in support of nausea as the main stimulus to AVP release. A similar pattern of AVP release without OT release was found after administration of cholecystokinin (CCK). Although most monkeys vomited in response to 10 micrograms/kg of CCK, a significant increase in plasma AVP levels also was produced with a dose of 1 microgram/kg, which did not produce emesis in any animal. These findings are in marked contrast with previous results in rats, which indicated that lithium chloride, copper sulfate, and CCK each stimulated OT rather than AVP release. Despite this interspecies difference, the significant neurohypophysial hormone secretion in response to both nausea-producing agents and CCK suggests that AVP secretion in monkeys, similar to OT secretion in rats, might reflect activation of central pathways mediating nausea and/or inhibition of food intake, even when overt illness is not produced.
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PMID:Vasopressin release in response to nausea-producing agents and cholecystokinin in monkeys. 303 8

1. Substitution of chloride by isethionate reduces the short circuit current (SCC) and increases the potential of isolated frog skin. In sodium isethionate Ringer antidiuretic hormone and choline chloride increase the SCC, whereas theophylline is ineffective.2. Frog skins treated on the outside with copper ions always show an increased potential when bathed in normal Ringer solution. The SCC may be moderately increased or decreased.3. Theophylline increases skin thickness and cell volume in non-short-circuited skins.4. The ways in which the theophylline-induced increase in chloride permeability affects sodium transport is discussed, together with the requirements for a permeant anion in both short- and open-circuited skins.
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PMID:The effects of anions on sodium transport. 576 32

Copper inhibits the hydro-osmotic response to vasopressin in the urinary bladder of Bufo marinus at a site proximal to cyclic AMP production. This effect is not reversed by washing in Cu2+ -free Ringer's solution but is overcome by serosal addition of reducing agents, suggesting that vasopressin responsiveness in this tissue is modulated by either the redox potential or the sulfhydryl content of the serosal membrane.
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PMID:Reversal of copper-induced inhibition of vasopressin responsiveness by reducing agents. 627 80

Recent amino acid sequence data suggest that trypsin-like and carboxypeptidase B-like activities are required for the processing of pituitary prohormones--e.g., pro-opiocortin (pro-adrenocorticotropin/lipotropin) and provasopressin in secretory granules. In this study the existence of a carboxypeptidase B activity in purified secretory granules from anterior, intermediate, and neural lobes of rat pituitary has been examined. A carboxypeptidase B activity that cleaved the COOH-terminal -Lys-Lys-Arg residues from the adrenocorticotropin fragment ACTH-(1-17) (a potential hormone product liberated from pro-opiocortin by a trypsin-like enzyme) was detected in anterior and intermediate lobe granules. A similar carboxypeptidase B activity was also present in purified secretory granules from rat pituitary neural lobes that cleaved the -Lys-Arg residues from [Arg8]vasopressin-Gly-Lys-Arg, a potential product cleaved from provasopressin. Secretory granule carboxypeptidase(s) from the three lobes of the pituitary was shown to cleave 125I-[Met]enkephalin-Arg6 to form 125I-[Met]enkephalin as well. 125I-[Met]Enkephalin was used as a model substrate for the quantitative assay of pituitary carboxypeptidase activity. The carboxypeptidase B in secretory granules from all three lobes was shown to be active at pH 5.5, but not at pH 7.4. Inhibition by the zinc metallocarboxypeptidase inhibitors guanidinopropylsuccinic acid, aminomercaptosuccinic acid, benzylsuccinic acid, 2-mercaptomethyl-3-guanidinoethylthiopropanoic acid, and the potato carboxypeptidase B inhibitor, and inhibition by the metal chelators EDTA and 1,10-phenanthroline demonstrate metal ion dependence of the pituitary granule carboxypeptidase activities. However, Co2+ stimulated the secretory granule carboxypeptidase B activities. Thiol protease inhibitors such as Cu2+ and p-chloromercuriphenylsulfonic acid also inhibited the activity. Thus, the secretory granule carboxypeptidase B-like activities in all three lobes of the pituitary appear to be similar thiol-metallopeptidases that differ from other carboxypeptidase activities previously described and may play an exclusive role in hormone biosynthesis in the pituitary.
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PMID:Carboxypeptidase B-like converting enzyme activity in secretory granules of rat pituitary. 632 44

Rat hepatic zinc thionein levels can be modulated by a variety of external and internal stimuli. Metals, such as zinc or copper, induce levels 20 to 50 fold over controls. Catecholamines can increase levels 10 to 20 fold, while glucocorticoids, such as dexamethasone, can increase levels modestly by 2-6 fold. We have investigated the ability of additional hormones, which have receptors on hepatocytes, to modulate the levels of hepatic zinc thionein. Glucagon, angiotensin II, and Arg-vasopressin were administered intravenously and intraperitoneally, one time and three times, over an 11 hour period. Zinc thionein levels in rat liver were increased 1.7 to 5.6 fold by glucagon and 1.7 to 3.6 fold by angiotensin II, but not at all by Arg-vasopressin, as compared to appropriate controls. Glucagon and angiotensin II, when administered in vivo, can modulate zinc thionein levels in rat liver to an extent similar to glucocorticoids. Hepatic zinc thionein levels must now be recognized to be affected in vivo by metals, glucocorticoids, catecholamines, and polypeptide hormones.
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PMID:Effects of glucagon, Arg-vasopressin, and angiotensin II on rat hepatic zinc thionein levels. 651 26


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