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)

A linear vasopressin antagonist, Phaa-D-Tyr(Me)-Phe-Gln-Asn-Arg-Pro-Arg-Tyr-NH2 (Linear AVP Antag) (Phaa = Phenylacetyl), was monoiodinated at the phenyl moiety of the tyrosylamide residue at position 9. This antagonist appeared to be a highly potent anti-vasopressor peptide with a pA2 value in vivo of 8.94. It was demonstrated to bind to rat liver membrane preparations with a very high affinity (Kd = 0.06 nM). The affinity for the rat uterus oxytocin receptor was lower (Ki = 2.1 nM), and affinities for the rat kidney- and adenohypophysis-vasopressin receptors were much lower (Ki = 47 nM and 92 nM, respectively), resulting in a highly specific vasopressin V1a receptor ligand. Autoradiographical studies using rat brain slices showed that this ligand is a good tool for studies on vasopressin receptor localization and characterization.
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PMID:A radioiodinated linear vasopressin antagonist: a ligand with high affinity and specificity for V1a receptors. 182 14

An investigation was undertaken to examine the effects of vasopressin on blood pressure and perfusion of the cortical and papillary regions of the kidney, and to determine the receptor subtype involved. Pentobarbitone-anaesthetized rats were used and laser-Doppler flowmetry applied to measure regional renal haemodynamics. Infusion of vasopressin at 10, 20 and 40 mU kg-1 min-1 caused dose-related increases in blood pressure and reductions in cortical and papillary perfusion of approximately 21, 35 and 41%, respectively at the highest dose. Administration of the V1-receptor antagonist, [1-(beta-mercapto-beta,beta-cyclopentamethylene propionic acid), 2-(o-methyl)tyrosine]-Arg8-vasopressin, at 1 microgram kg-1 plus 5 micrograms kg-1 h-1 or four times this dose had no effect on the basal levels of any variable. Vasopressin administration during the low dose of antagonist increased blood pressure and reduced papillary perfusion, the magnitudes of which were only slightly less than those obtained in the absence of the drug, whereas there was a significant attenuation of the response in cortical perfusion. During infusion of the V1 antagonist at 4 micrograms kg-1 plus 20 micrograms kg-1 h-1, vasopressin had no effect on either blood pressure or renal haemodynamics. Infusion of the V2 antagonist, [d(CH2)5, D-Phe2, Ile4, Arg8, Ala9-NH2]-vasopressin at 1 microgram kg-1 plus 5 micrograms kg-1 h-1, and twice this dose had no effect on the basal value of any variable and had no effect on the ability of vasopressin to induce an increase in blood pressure or cause reductions in renal cortical and papillary perfusions. However, the administration of the V2 antagonist at 4 micrograms kg-1 plus 20 micrograms kg-1 h-1 significantly attenuated blood pressure, cortical and papillary perfusion responses to the vasopressin. These studies have shown that vasopressin, given at doses which increased blood pressure, caused dose-related decreases in perfusion of renal cortex as well as the papilla. The data further show that these systemic and renal actions were mediated primarily by V1-receptors and that the contribution of V2-receptors at these vascular beds was very small.
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PMID:An investigation into the influence of vasopressin on perfusion of the cortex and papilla of the rat kidney. 183 21

Chemical and photoaffinity cross-linking experiments as well as ligand affinity blotting techniques were used to label the V1 vasopressin receptor. In order to determine the optimal reaction conditions, pig liver membranes were incubated with 5 nM [8-lysine]vasopressin (LVP) labeled with 125I and then cross-linked with the use of DMS (dimethyl suberimidate), EGS [ethylene glycol bis(succinimidyl succinate)] or HSAB (hydroxysuccinimidyl p-azidobenzoate) at different final concentrations. Consistently, EGS was found to label with high yield one band of Mr 60,000 in rat and pig liver membranes when used at a final concentration between 0.05 and 0.25 mM. The protein of Mr 60,000 is labeled in a concentration-dependent manner when pig liver membranes are incubated with increasing concentrations of 125I-LVP and then cross-linked with EGS. The label was displaced by increasing concentrations of unlabeled LVP or d(CH2)5 [Tyr2(Me),-Tyr9(NH2)]AVP (V1/V2 antagonist). A protein band of similar molecular mass was cross-linked with 125I-LVP in rat liver membranes. The reaction was specific since the incorporation of label into the protein of Mr 60,000 was inhibited by LVP, [8-arginine]vasopressin (AVP), the V1/V2-antagonist, and the specific V1-antagonist d(CH2)5 [Tyr2(Me)]AVP, only partially by [des-Gly9]AVP (V2-agonist) and by oxytocin, and not at all by angiotensin II. Incubation of nitrocellulose containing membrane proteins from pig liver with 125I-LVP showed the labeling of a band of Mr 58,000 that is inhibited by an excess of unlabeled LVP. This band of Mr 58,000 seems to correspond with the protein of Mr 60,000 revealed by the cross-linking experiment.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Identification of the V1 vasopressin receptor by chemical cross-linking and ligand affinity blotting. 183 97

We have designed and synthesized a biotinylated vasopressin antagonist which is a selective probe for studying the V1a subtype of vasopressin receptor. Initially we synthesized the novel vasopressin analogue d(CH2)5Tyr(Me)2LysNH2(9)AVP (ALVP). Biotinamidocaproate was subsequently coupled to the epsilon-amino group of ALVP to generate the novel biotinylated probe d(CH2)5Tyr(Me)2Lys(N epsilon-biotinamido-caproate)NH2(9)AVP (ALBtnVP). Pharmacological characterization of ALVP and ALBtnVP established that both ligands were high affinity antagonists at V1a receptors, and that both displayed marked V1a/V2 selectivity. The observation that receptor-bound ALBtnVP was bi-functional, and thereby able to bind conjugated derivatives of avidin or streptavidin, allowed ALBtnVP to be utilized as a selective probe for V1a receptors. This strategy allowed the visualization of V1a receptors on the surface of WRK-1 cells and hippocampal neurons, by using streptavidin-gold with electron microscopy and fluorescein-avidin with light microscopy. We conclude that ALBtnVP is a useful probe for V1a receptors.
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PMID:A selective biotinylated probe for V1a vasopressin receptors. 184 40

A bovine neurophysin II S-methyl-Cys-Tyr-Phe-NH2 complex has been crystallized using ammonium sulfate as the precipitating agent. The crystals are orthorhombic, the space group is either I222 or I2(1)2(1)2(1) with a = 124.9 A, b = 69.6 A and c = 151.5 A. The crystals diffract to at least 3.0 A resolution. Based on one neurophysin tetramer per asymmetric unit, the Matthews coefficient is calculated to be 3.92 with a solvent content of 69%.
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PMID:Crystals of a bovine neurophysin II tripeptide complex. 194 66

Four labelled ligands, [3H]arginine vasopressin ([3H]AVP), [3H]oxytocin ([3H]OT), [3H]d(CH2)5[Tyr(Me)2]AVP ([3H]VPA), and [125I]d(CH2)5[Tyr(Me)2-Thr4-Orn8-Tyr(NH2)9]OT([125I]OTA] and nine unlabelled analogues exhibiting enhanced selectivity for rat oxytocin (OT) and vasopressin (VP) receptors were used to characterize OT and VP receptors on myometrial membranes from non-pregnant and pregnant human uteri. On membranes from non-pregnant uteri, [3H]AVP, [3H]VPA, and [125I]OTA labelled with high affinity (Kd values: 3.2, 2 and 0.8 nM, respectively) a major and apparently homogeneous population of sites, the ligand selectivity of which resembled that of rat V1a VP receptors. On membranes from pregnant and non-pregnant uteri, [3H]OT labelled a single population of high-affinity sites that could be distinguished from VP receptors on the basis of ligand selectivity. Several analogues (in particular [125I]OTA) that are highly selective for rat OT receptors exhibited a much less pronounced selectivity for human OT receptors. Experiments with [3H]VPA allowed detection of VP receptors on myometrical membranes from pregnant uteri and confirmed that only OT but not VP receptors increase during pregnancy in humans.
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PMID:Labelling of vasopressin and oxytocin receptors from the human uterus. 196 9

1. Oxytocin receptors in the uterus of the brushtail possum (T. vulpecula) were characterized by radioreceptor assay and compared with those of the sheep and rat uterus. 2. A single oxytocin binding site was found with an affinity (Kd) and receptor concentration (Ro) of 3.0 +/- 0.8 nmol/l and 200 +/- 60 fmol/mg protein, respectively (SEM; n = 5). The receptor was stable at -20 degrees C; divalent ions were required for optimum binding. 3. Competitive displacement curves with related peptides showed the following order of specificity: vasotocin greater than oxytocin greater than mesotocin = arginine-vasopressin = [Thr4, Gly7]-oxytocin greater than lysine-vasopressin = isotocin much greater than [d(CH2)5, D-Phe2, Ile4, Ala9-NH2]-AVP. 4. It was concluded that oxytocin receptors in the possum have similar characteristics to those of placental mammals.
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PMID:Uterine oxytocin receptors in an Australian marsupial, the brushtail possum, Trichosurus vulpecula. 196 6

The role of plasma membrane fluidity in the regulation of kidney tubule water permeability has been uncertain. We have used new methods to image the fluorescence anisotropy of fluidity-sensitive fluorophores (Fushimi, Dix, and Verkman. Biophys. J. 57: 241-254, 1990) to quantitate membrane fluidity in cells of the vasopressin-sensitive cortical collecting tubule (CCT) and water-impermeable cortical thick ascending limb (CTAL). Isolated tubule segments from rabbit kidney were perfused in vitro, and apical or basolateral plasma membranes were stained with trimethylammonium diphenylhexatriene (TMA-DPH). TMA-DPH anisotropy (r) was imaged quantitatively by an epifluorescence microscope equipped with rotatable polarizers; TMA-DPH nanosecond lifetime (tau) was measured by flash-lamp excitation and gated photomultiplier detection. In CCT, apical membrane r (0.254 +/- 0.003) was similar to basolateral r (0.252 +/- 0.005). Serosal vasopressin at a dose that increased water permeability greater than 10-fold (250 microU/ml) did not affect apical membrane r (delta r = 0.002 +/- 0.003; 7 tubules). A 0.002 change in r was less than that produced by a 2 degrees C temperature variation. In CTAL, apical membrane r was 0.249 +/- 0.002, similar to r from basolateral membrane of proximal tubule (0.24), but much less than that of proximal tubule apical membrane (0.29). These results establish methodology to quantitate fluidity in intact kidney tubule segments and provide the first measurements of plasma membrane fluidity in CTAL and CCT. Our results suggest that regulation of bulk membrane fluidity in CCT apical membrane is not a component of the hydrosmotic action of vasopressin and that low apical membrane fluidity is not responsible for the low water and NH3 permeabilities in CTAL.
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PMID:Relationship between vasopressin-sensitive water transport and plasma membrane fluidity in kidney collecting tubule. 198 73

A series of vasopressin analogs with various amino acid tail modifications were tested for antidiuretic agonist and antagonist (water diuretic) activity in the water-loaded indomethacin-treated and hydropenic dogs, respectively. Changing the carboxy terminus from Cys6-Pro7-Arg8-NH2 in SK&F 101926 to Cys6-Arg7-NH2 or to D-Cys6-Pro7-Arg8-NH2 or to D- or L-Cys6-Arg7-D-Arg8-NH2 reduced antidiuretic agonist and increased water diuretic activity. Replacement of the sulfur atoms in the cysteine residues with methylene groups further reduced the antidiuretic agonist activity of all carboxy terminus-modified compounds which possessed full agonist activity. It also increased the water diuretic activity of those disulfide analogs with both weak agonist and antagonist activity. These results indicate that alterations in the geometry of the hexapeptide ring and in the stereochemical relationship between the ring and the carboxy terminus of the molecule substantially modify the in vivo agonist and antagonist activity of vasopressin analogs.
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PMID:Vasopressin antidiuretic agonist and antagonist activity in dogs: structural and stereochemical relationship between bridge and carboxyl terminus. 198 64

We prepared nine analogues (1-9) of MCPA-D-Phe-Phe-Ile-Asn-Cys-Pro-Arg-Gly-NH2, [MCPA1, D-Phe2, Phe3, Ile4, Arg8]oxytocin (MCPA = beta-mercapto-beta,beta-pentamethylenepropionic acid), a potent antagonist of the rat uterotonic action of oxytocin (OT). We replaced D-Phe with D-Trp and made [MCPA1,D-Trp2,Phe3,Ile4,Arg8]OT (1), which had OT pA2 of 7.51, somewhat higher than that of the D-Phe2 antagonist which has OT pA2 = 7.35 in our rat uterotonic assay. Both compounds are equipotent as antagonists of [Arg8]vasopressin in the rat antidiuretic assay, with pA2 = 8.1. Other substitutions gave [MCPA1,D-Trp2,4-Cl-Phe3,Ile4,Arg8]OT, (2), OT pA2 7.44; [MCPA1,D-Trp2,Phe3,Ile4,3,4-dehydro-Pro7,Arg8]OT (3), OT pA2 = 7.42; [MCPA1,D-Trp2,Phe3,Arg8]OT (4), OT pA2 = 7.58; [MCPA1,D-Trp2,Phe3,Arg8,Gly9-NHEt]OT (5), OT pA2 = 7.49; [MCPA1,D-Trp2,Ile4,Arg8]OT (6), OT pA2 = 7.46; [MCPA1,D-Trp2,Val4,Arg8]OT (7), OT pA2 = 7.58; [MCPA1,D-Trp2,Thr4,Arg8]OT (8), OT pA2 = 7.48; and finally, [MCPA1,D-Trp2,Arg8]OT (9), which was a more potent and more selective OT antagonist, with OT pA2 = 7.77 in the uterotonic assay and ADH pA2 less than 5.9 in the antidiuretic assay and hence is an important lead for the design of OT antagonists.
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PMID:Design of potent oxytocin antagonists featuring D-tryptophan at position 2. 199 88


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