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)

Adenylate cyclase and the [8-lysine]vasopressin receptor were solubilized from pig kidney medulla membranes using the nonionic detergent Triton X-100. Optimal conditions for solubilization were under continuous stirring in a medium containing 0.5% (/v) Triton X-100, 100 mM Tris-HCl, pH 8, and 10 mM MgCl2. Both adenylate cyclase activity and [3H][8-lysine]vasopressin binding activity were recovered in a -26,000 X g supernatant of detergent-treated membranes. The yield of solubilized adenylate cyclase was nearly 100%. The soluble enzyme was no longer sensitive to antidiuretic hormone but was slightly activated by sodium fluoride. The affinity of the soluble receptor for [8-lysine]vasopresin was les than that of the membrane-bound receptor (mean apparent Km values, respectively 10(-7) M and 2 X 10(-8) M), however binding cooperativity was preserved. Hill coefficients were 1.42 for the soluble receptor and 1.50 for the membrane receptor. The soluble receptor discriminated as efficiently as did the membrane receptor between [8-lysine-a1vasopressin and oxytocin. The yield of spolubilized receptor was only 30% despite the fact that all binding activity had disappeared from the residual pellet of detergent-treated membranes. When the membranous receptors were occupied before solubilization and the latter was performed under conditions in which dissociation of the hormone-receptor comples is slow, i.e. at low temperature, 65% to 100% of the hormone-receptor complex was recovered in the soluble fraction. The soluble hormone-receptor complex partially dissociated on rewarming whereas the free hormone concentration was kept unchanged in the medium. The residual binding capacity, which was 30% of the initial value, was identical with that determined when the receptor was solubilized in free form before incubation with labeled hormone. It was concluded that (a) solubilization of the receptor molecules was complete, (b) during solubilization two forms of the receptor appear, of which only one is accessible to the hormone, (c) occupancy of the receptor by the hormone prevented the formation of the nonaccessible form, and (d) some component or components of the soluble fraction might be responsible for the loss in apparent affinity.
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PMID:Solubilization of the [8-lysine]vasopressin receptor and adenylate cyclase from pig kidney plasma membranes. 17 Feb 74

The effects of various doses of intravenous vasopressin on mesenteric arterial blood flow, intestinal oxygen consumption, and cardiac output in anesthetized dogs were investigated. Optimal dose rate of intravenous vasopressin was found to be 3.0 mU/kg/min. At this dose rate, mesenteric arterial blood flow, intestinal oxygen consumption, and cardiac output decreased by 57%, 57% and 26%, respectively. Increasing the dose rate to 8.0 mU/kg/min did not offer significant gains. Maximum effect was observed 20 min after the beginning of the infusion. The effects disappeared 10-20 min after the infusion was discontinued, with the exception of superior mesenteric blood flow which showed a rebound increase. We conclude that in the anesthetized dog, intravenous infusions of vasopressin at low dose rates (3.0 mU/kg/min) substantially reduce mesenteric blood flow and intestinal oxygen extraction with moderate reduction of cardiac output. Possible clinical applications of low dose intravenous infusions of vasopressin would include reduction of portal hypertension and bowel protection during radiation therapy.
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PMID:Effects of intravenous vasopressin on canine mesenteric arterial blood flow, bowel oxygen consumption, and cardiac output. 41 36

Several potential photoaffinity analogues of the peptide hormone vasopressin (VP) were prepared by classical solid-phase peptide synthesis using two different pathways. Peptide sequences were built by introduction of (a) Nar-protected aminophenylalanine or (b) nitrophenylalanine in the photolabeling position. Conversion to the azido peptide was completed in pathway a after cleavage and before purification and in pathway b from small quantities of purified nitrophenylalanine-containing precursor peptides. V1 receptor binding properties were measured using membranes prepared from rat liver cells. The binding potential of agonistic VP structures was abolished by the introduction of an azido or a nitro group into the aromatic side chain at position 3. Cyclo desamino-beta,beta-dialkyl-Cys1-type VP antagonist structures were prepared with the photoactivable moiety in position 2 and an iodination residue in position 9. One particular compound, [Dmpa1, Phe(N3)2, Val4, Lys8,D-Tyr9]VP (8), containing beta,beta-dimethyl-beta-mercaptopropionic acid in position 1, had excellent binding properties, both in the radioiodinated (Kd = 4.8 +/- 1.9 x 10(-10) M) and noniodinated form (Kd = 6.4 +/- 0.98 x 10(-10) M). The analogues with long-chain beta-alkylation (diethyl and pentamethylene) and the linear antagonist photolabel showed significantly less affinity. Optimal binding properties were obtained within a very narrow range of hydrophobicity; greater or lesser hydrophobicity was correlated to less potent binding. The precursor analogues, containing nitrophenylalanine, displayed a structure-activity relationship similar to that of the azido peptides. The most potent analogues will be used for receptor labeling studies. A linear antagonist structure having a photosensitive group in position 1, has also been prepared, but this compound displayed much less affinity than the cyclic antagonists. The most potent compounds were also highly selective for the V1 receptor and did not recognize the V2 receptor from other preparations.
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PMID:Preparation and biological activities of potential vasopressin photoaffinity labels. 173 23

Specific binding sites for somatostatin have been identified in cytosolic fraction of rabbit kidney (cortex and outer medulla) using 125I-Tyr11-somatostatin. The binding was saturable and reversible, as well as time and temperature dependent. Optimal pH for binding was observed at about 7.4. Scatchard plots were compatible with the existence of two classes of binding sites: a first class with a high affinity (Kd = 40 nM) and a low binding capacity (2.0 pmol somatostatin/mg protein) and a second class with a low affinity (Kd = 222 nM) and a high binding capacity (114.3 pmol somatostatin/mg protein). Vasoactive intestinal peptide, neurotensin, substance P, Leu-enkephalin and vasopressin had practically no effect on somatostatin binding. The properties of these binding sites strongly support the concept that somatostatin could behave as a regulatory peptide on the rabbit kidney.
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PMID:Evidence for somatostatin binding sites in rabbit kidney. 287 91

Soluble extracts prepared from quiescent Swiss mouse 3T3 cells that had been briefly exposed to various mitogens exhibited a 2- to 3-fold elevation in phosphorylating activities toward ribosomal protein S6 and a synthetic peptide, Arg-Arg-Leu-Ser-Ser-Leu-Arg-Ala (RRLSSLRA), patterned after a phosphorylation site sequence from S6. Optimal activation of the phosphorylating activity occurred within 15-20 min of exposure of the cells to platelet-derived growth factor (10 ng/ml), epidermal growth factor (100 nM), and insulin (100 nM), and 2-5 min after 12-O-tetradecanoylphorbol-13-acetate (TPA) (100 nM) treatment. Fractionation of the cytosolic extracts from mitogen- or TPA-treated cells on Sephacryl S-300, TSK-400, and DEAE-Sephacel columns gave results suggesting that a single stimulated kinase accounted for the enhanced S6 and RRLSSLRA phosphorylating activities. The mitogen-activated kinase had an apparent Mr of about 85,000 as determined with Sephacryl S-300, but eluted with an apparent Mr of 26,000 from a TSK-400 high pressure liquid chromatography column. The S6 kinase was also stimulated in cytosols from insulin-like growth factor 1- (100 nM), vasopressin- (250 nM), prostaglandin F2 alpha- (250 nM), and 10% fetal calf serum-treated cells but not from quiescent cells exposed to beta-transforming growth factor (2 ng/ml). TPA, vasopressin and prostaglandin F2 alpha appeared to stimulate this kinase via a protein kinase C-dependent mechanism, since the responses to these hormones, but not to platelet-derived growth factor, epidermal growth factor, and insulin, were lost in protein kinase C-depleted cells.
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PMID:Mitogen-activated S6 kinase is stimulated via protein kinase C-dependent and independent pathways in Swiss 3T3 cells. 330 94

Cytosolic [Ca2+] has been measured by using the Ca2+-sensitive indicator quin2 in rat liver cells. Optimal loading and hydrolysis have been obtained by equilibrating the cells with 50 microM quin2 acetoxymethyl ester for 150 s. The increase in [Ca2+]i initiated by noradrenaline and vasopressin was reduced but not abolished by removing external Ca2+.
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PMID:Cytosolic free Ca2+ in isolated rat hepatocytes as measured by quin2. Effects of noradrenaline and vasopressin. 669 2

The pressure/volume relationship of toad urinary bladders was measured from 0 to 50 cmH2O. Optimal bladder capacity was derived by extrapolation of the pressure/volume curve to a pressure of 0 cmH2O. The compliance of the bladder wall was calculated from the slope of the pressure/volume curve at intraluminal pressures above 10 cmH2O. Neither vasopressin nor atropine had any effect on bladder wall compliance. Bladders filled with one-fifth strength Ringer fluid and suspended in full-strength Ringer lost weight at 0.02 (at half-optimal capacity), 0.08 (at optimal capacity), and 0.26 mg.min-1.cm-2 (at supra-optimal capacity, 25 cmH2O) in the absence of vasopressin. With 20 mU/ml vasopressin, bladders lost weight at 1.08 (at half-optimal capacity), 1.55 (at optimal capacity), and 1.74 mg.min-1.cm-2 (at supra-optimal capacity, 25 cmH2O). When bladder wall tension was raised from 2,102 to 28,383 dyn/cm, the permeability to [14C]mannitol increased from 8 X 10(-7) to 39 X 10(-7) cm/s. Electron microscopy of bladders fixed at a wall tension of 17,572 dyn/cm showed flattening of the microvilli, rupture of the apical cell membranes of some granular and mitochondria-rich epithelial cells, but no obvious alteration in the tight junctions. This study suggests that stretching the apical plasma membrane to the point at which it ruptures in some cells does not alter the capacity of vasopressin to induce its characteristic increase in permeability to water of this membrane.
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PMID:Toad bladder compliance and water permeability in response to stretch. 680 Feb 64

Desmopressin is a widely used hemostatic drug. It is a synthetic analogue of the natural hormone vasopressin, but, in contrast to vasopressin, it has no pressor activity. The effect is immediate, with two- to sixfold increases in the plasma concentrations of coagulation factor VIII, on Willebrand factor, and tissue plasminogen activator, and increases in platelet adhesiveness of comparable magnitude. Desmopressin is used in patients with mild hemophilia A, von Willebrand's disease, congenital platelet dysfunction, or acquired platelet dysfunction due to uremia or intake of such drugs as aspirin. It may also be used to reduce surgical blood loss in patients without known bleeding diathesis. Optimal hemostatic effect is achieved with a dosage of 0.3 micrograms/kg given intravenously. Other routes of administration are subcutaneous injection or intranasal spray. The latter proved to be efficient for home treatment of patients with bleeding disorders.
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PMID:Desmopressin (DDAVP) and hemostasis. 794 3

This study examines the effects of antihypertensive therapy on platelet cytosolic calcium [Ca2+]i responses to low-density lipoprotein cholesterol (LDL) and vasopressin (AVP) in 15 patients (50-80 years) participating in the Hypertension Optimal Treatment International Study. All patients (diastolic blood pressure (DBP) > or = 100 mm Hg and < or = 115 mm Hg) were treated with the calcium antagonist felodipine (10 mg p.o.) with or without addition of enalapril (up to 20 mg daily as needed) to lower diastolic pressures to < 85 mm Hg. This antihypertensive therapy lowered DBP (104 +/- 0.8 to 78 +/- 1.6 mm Hg, P < 0.0001), but had no effect on basal [Ca2+]i or AVP-stimulated [Ca2+]i responses. Basal platelet [Ca2+]i following antihypertensive therapy (49 +/- 3.4 ng/ml) were not different from those prior to therapy (52 +/- 4.7 ng/ml). Additionally, [Ca2+]i responses to AVP following therapy (554 +/- 74 units) were not different from those prior to treatment (595 +/- 49 units). Following antihypertensive therapy, [Ca2+]i responses to 200 micrograms/ml of LDL were decreased fourfold (P < 0.05). These results suggest that antihypertensive therapy with a calcium channel blocker may potentially impact the atherogenic process by reducing the platelet [Ca2+]i rise, and potentially the aggregatory response, to LDL.
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PMID:Effects of antihypertensive therapy on platelet cytosolic calcium responses to low density lipoprotein cholesterol. 873 36

A solid-phase enzyme immunoassay procedure for detecting natural antibodies to vasopressin (VP) is developed. For this purpose, a VP antigen is synthesized on polymer matrix. Optimal conditions of enzyme immunoassay for detecting antibodies to this antigen in the sera of donors and patients with systemic lupus erythematosus (SLE) are selected. The level of anti-VP antibodies is constant in donors and shifted in SLE patients. Changes in the level of natural antibodies to VP correlate with immunochemical parameters.
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PMID:[Immunoenzyme assay for detection of natural antibodies against vasopressin in systemic lupus erythematosus]. 1035


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