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Query: UNIPROT:P01185 (vasopressin)
 23,126 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The role of hormone receptor lateral mobility in signal transduction was studied using a cellular system in which the receptor mobile fraction could be reversibly modulated to largely varying extents. The G-protein-coupled vasopressin V2-type receptor was labeled in LLC-PK1 renal epithelial cells using a fluorescent analogue of vasopressin, and receptor lateral mobility measured using fluorescence microphotolysis (fluorescence photobleaching recovery). The receptor mobile fraction (f) was approximately 0.9 at 37 degrees C and less than 0.1 at 10 degrees C, in accordance with previous studies. When cells were incubated for 1 h at 4 degrees C without hormone, and then warmed up to 37 degrees C and labeled with the vasopressin analogue, f increased from approximately 0.4 to 0.8 over approximately 1 h. The apparent lateral diffusion coefficient was not markedly affected by temperature pretreatment. Studies with radiolabeled vasopressin indicated that temperature pretreatment influenced neither receptor number nor binding/internalization kinetics. F-actin staining revealed that temperature change resulted in reversible changes of cytoskeletal structure. The maximal rate of in vivo cAMP production at 37 degrees C in response to vasopressin, but not to forskolin (receptor-independent agonist), was also markedly influenced by preincubation of cells at 4 degrees C, thus paralleling the effects of temperature preincubation on f. A linear correlation between f and maximal cAMP production was observed, suggesting that the receptor mobile fraction is a key parameter in hormone signal transduction in vivo. We conclude that mobile receptors are required to activate G-proteins, and discuss the implications of this for signal transduction mechanisms.
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PMID:Vasopressin V2-receptor mobile fraction and ligand-dependent adenylate cyclase activity are directly correlated in LLC-PK1 renal epithelial cells. 164 25

The neurohypophyseal neuropeptides (Arg8)-vasopressin (AVP) and [pGlu4,Cyt6]AVP-(4-8) (where pGlu is pyroglutamic acid and Cyt is cystine) facilitate the retention of one-trial-learning passive avoidance behavior in rats when administered into the cerebral ventricle immediately after the learning trial. The fragment [pGlu4,Cyt6]AVP-(4-8) was considerably more effective than AVP. Oxytocin (OXT) and [pGlu4,Cyt6]OXT-(4-8) have the opposite effect and attenuate passive avoidance behavior also when administered into the cerebral ventricle after the learning trial. Again the fragment was more active than the parent molecule. The ancient arginine-containing neurohypophyseal hormone vasotocin in "high" doses (10ng) had a vasopressin-like effect and in "low" doses (0.1 ng) had an OXT-like effect on passive avoidance behavior. Because both vasopressinergic (V1) and oxytocinergic receptors have been demonstrated in the central nervous system, we asked whether specific antagonists of the V1, V2, and OXT receptor could antagonize the effects of these neuropeptides on passive avoidance behavior. The three antagonists were approximately equally active in blocking the effect of vasopressin, whereas the fragment [pGlu4]AVP-(4-8) and the high dose of vasotocin were more readily blocked by the OXT antagonist. The attenuating effect of OXT, the fragment [pGlu4,Cyt6]OXT-(4-8), and the low dose of vasotocin was markedly reduced by the OXT antagonist. This effect could also be reduced by pretreatment with the V1 antagonist but not with the V2 antagonist. These results suggest the existence of a separate neurohypophyseal hormone receptor complex in the brain affecting memory processes that differs from the peripheral V1, V2, and OXT receptor.
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PMID:Interactive effects of neurohypophyseal neuropeptides with receptor antagonists on passive avoidance behavior: mediation by a cerebral neurohypophyseal hormone receptor? 184 26

Vasopressin receptors were demonstrated on human peripheral blood mononuclear cells (PBMC) by using the radioiodinated analog of d(CH2)5[Tyr(Me2)Thr4Tyr-NH2(9)]OVT (OTA). Binding of this ligand was time-dependent, specific, and saturable. Scatchard analysis of [125I]-OTA binding at equilibrium revealed a dissociation constant of 0.47 +/- 0.17 nM. A considerable sex difference in binding capacity was observed. PBMC from female donors expressed an approximately sevenfold higher receptor density than PBMC from male donors, while no change of Kd was apparent. Throughout the menstrual cycle the maximal binding capacity was relatively constant. Competition studies with vasopressin and oxytocin analogs showed that this putative receptor site on PBMC is comparable in receptor specificity to the human V1 receptor on myometrial tissue and blood platelets, but slightly different from the rat neurohypophyseal hormone receptor classes. Our findings provide further evidence of a remarkable species and sex difference of vasopressin and oxytocin receptors, regarding their ligand selective binding properties. The presence of the putative arginine-vasopressin receptors on PBMC may provide a molecular basis for several arginine-vasopressin induced effects on the chemistry and function of circulating mononuclear cells.
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PMID:Vasopressin receptor capacity of human blood peripheral mononuclear cells is sex dependent. 213 99

The present work examines lateral mobility of the vasopressin V1-type receptor, representing the first determination of lateral mobility of a hormone receptor coupled to phospholipase C activation. The V1-receptor of A7r5 smooth muscle cells was characterized for [Arg8] vasopressin (AVP) binding properties and affinity for the fluorescent vasopressin analogue 1-deamino[8-lysine (N6-tetramethylrhodamylaminothiocarbonyl)] vasopressin (TR-LVP). TR-LVP was biologically active in A7r5 cells, inducing inositol 1,4,5-trisphosphate turnover in similar fashion to AVP. TR-LVP was used to specifically label the V1-receptor of living A7r5 cells, and lateral mobility of the V1-receptor was measured using the technique of fluorescence microphotolysis. The apparent lateral diffusion coefficient (D) at 37 degrees C was 5.1 x 10(-10) cm2/s, falling to 2.9 x 10(-10) cm2/s at 13 degrees C. These D values are higher than comparable values for the adenylate cyclase-activating vasopressin V2-receptor of LLC-PK1 renal epithelial cells analysed with the same fluorescent ligand. In contrast to the V2-receptor, no marked temperature dependence was observed for the V1-receptor mobile fraction (f). From 37 degrees C to 13 degrees C, f was relatively low (between 0.4 and 0.5) consistent with V1-receptor immobilization through internalization, which is rapid even at room temperature in A7r5 cells. These differences between V1- and V2-receptor lateral mobility are discussed in terms of the implications for their respective signal transduction systems.
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PMID:Lateral mobility of the phospholipase C-activating vasopressin V1-type receptor in A7r5 smooth muscle cells: a comparison with the adenylate cyclase-coupled V2-receptor. 214 82

Uptake of 22Na+ by liver plasma membrane vesicles, reflecting Na+ transport by (Na+, K+)ATPase or Na+/H+ exchange was studied. Membrane vesicles were isolated from rat liver homogenates or from freshly prepared rat hepatocytes incubated in the presence of [Arg8]vasopressin or pervanadate and insulin. The ATP dependence of (Na+, K+)ATPase-mediated transport was determined from initial velocities of vanadate-sensitive uptake of 22Na+, the Na(+)-dependence of Na+/H+ exchange from initial velocities of amiloride-sensitive uptake. By studying vanadate-sensitive Na+ transport, high-affinity binding sites for ATP with an apparent Km(ATP) of 15 +/- 1 microM were observed at low concentrations of Na+ (1 mM) and K+ (1mM). At 90 mM Na+ and 60 mM K+ the apparent Km(ATP) was 103 +/- 25 microM. Vesiculation of membranes and loading of the vesicles prepared from liver homogenates in the presence of vasopressin increased the maximal velocities of vanadate-sensitive transport by 3.8-fold and 1.9-fold in the presence of low and high concentrations of Na+ and K+, respectively. The apparent Km(ATP) was shifted to 62 +/- 7 microM and 76 +/- 10 microM by vasopressin at low and high ion concentrations, respectively, indicating that the hormone reduced the influence of Na+ and K+ on ATP binding. In vesicles isolated from hepatocytes preincubated with 10 nM vasopression the hormone effect was conserved. Initial velocities of Na+ uptake (at high ion concentrations and 1 mM ATP) were increased 1.6-1.7-fold above control, after incubation of the cells with vasopressin or by affinity labelling of the cells with a photoreactive analogue of the hormone. The velocity of amiloride-sensitive Na+ transport was enhanced by incubating hepatocytes in the presence of 10 nM insulin (1.6-fold) or 0.3 mM pervanadate generated by mixing vanadate plus H2O2 (13-fold). The apparent Km(Na+) of Na+/H+ exchange was increased by pervanadate from 5.9 mM to 17.2 mM. Vesiculation and incubation of isolated membranes in the presence of pervanadate had no effect on the velocity of amiloride-sensitive Na+ transport. The results show that hormone receptor-mediated effects on (Na+, K+)ATPase and Na+/H+ exchange are conserved during the isolation of liver plasma membrane vesicles. Stable modifications of the transport systems or their membrane environment rather than ionic or metabolic responses requiring cell integrity appear to be involved in this regulation.
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PMID:Vasopressin, insulin and peroxide(s) of vanadate (pervanadate) influence Na+ transport mediated by (Na+, K+)ATPase or Na+/H+ exchanger of rat liver plasma membrane vesicles. 217 38

The lateral mobility of membrane-associated hormone receptors has been proposed to play an important role in signal transduction. Direct measurements, however, have shown that the receptors for insulin, epidermal growth factor and beta-adrenergic antagonists exhibit low mobility at physiological temperature. The present study, which represents the first report of lateral mobility of a polypeptide hormone receptor coupled to adenylate cyclase, yielded quite different results. The lateral mobility of the vasopressin renal-type (V2)-receptor was measured in the basal plasma membrane of cells of the LLC-PK1 porcine epithelial line, using the technique of fluorescence microphotolysis (photobleaching) and a rhodamine-labelled analogue of vasopressin. The analogue, 1-deamino[8-lysine(N6-tetramethylrhodamylaminothiocarbonyl)] vasopressin (TR-LVP) was synthesized and shown to have binding properties and biological activities very similar to those of Arg8-vasopressin (AVP). TR-LVP could be used to label specifically the V2-receptor of living LLC-PK1 cells, whereby LLC-PK1 cells incubated with TR-LVP in the presence of a 100-fold excess of AVP, or cells from the LLC-PK1 V2-receptor-deficient line M18 incubated with TR-LVP could be used as controls for non-specific binding. Using optical sectioning, specific receptor mobility could be measured both in the absence and presence of free TR-LVP. The V2-receptor was found to be largely mobile at 37 degrees C: the mobile fraction (f) was approximately 0.9, and the apparent lateral diffusion coefficient (D) approximately 3.0 X 10(-10) cm2/s. V2-receptor mobility greatly decreased with decreasing temperature: at 10 degrees C f was reduced to approximately 0.1.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The adenylate cyclase-coupled vasopressin V2-receptor is highly laterally mobile in membranes of LLC-PK1 renal epithelial cells at physiological temperature. 253 Oct 84

1. We have developed a plasma membrane preparation from the mucosal epithelium of rabbit gallbladder and have characterized the hormonal sensitivity of adenylate cyclase in this preparation. 2. Basal activity is low and is stimulated by GTP and GppNHp. Hormonal stimulation is largely dependent on exogenous guanine nucleotide. 3. Several prostaglandins (E1 approximately E2 greater than A1 greater than B1), vasoactive intestinal peptide and the beta-adrenergic agonist, isoproterenol, stimulate mucosal adenylate cyclase activity; a variety of peptides and neurotransmitters (secretin, cholecystokinin, arg-vasopressin, oxytocin, histamine, dopamine and serotonin) are without effect. 4. The data support the hypothesis that the inhibitory effect of prostaglandins, vasoactive intestinal peptide, and isoproterenol on gallbladder fluid absorption in certain species may be mediated by cyclic AMP. 5. The membrane preparation should be useful in further characterizing hormone receptor-transducer interactions of the gallbladder mucosal epithelium.
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PMID:Characterization of hormone-sensitive adenylate cyclase in rabbit gallbladder mucosa. 254 33

Bradykinin inhibits vasopressin-stimulated water transport in cortical collecting tubular cells. The biochemical mechanism of this effect was explored by means of primary cultures of rabbit cortical collecting tubular cells. Bradykinin was found to produce a rapid release of calcium from intracellular stores, an increase in sn-1,2-diacylglycerol levels, and a fivefold increase in membrane-bound protein kinase C activity, consistent with stimulation of phospholipase C and activation of protein kinase C in rabbit cortical collecting tubular cells. In addition, bradykinin produced a dose-dependent 46% inhibition of vasopressin-stimulated adenosine 3',5'-cyclic monophosphate (cAMP) formation. Pretreatment with the protein kinase C inhibitors, H-7 and staurosporine, reversed the bradykinin-mediated inhibition of vasopressin-stimulated cAMP accumulation. In contrast, pretreatment with either the phospholipase A2 inhibitor, mepacrine, or pertussis toxin did not prevent the inhibitory effect of bradykinin on vasopressin-stimulated cAMP production, suggesting that the effects are not mediated by prostaglandin E2 or activation of a pertussis-toxin sensitive guanine nucleotide regulatory protein (e.g., Gi). Because bradykinin also inhibits isoproterenol-stimulated cAMP formation but does not inhibit either basal-, forskolin-, or cholera toxin-stimulated cAMP accumulation, the site of this inhibition appears to involve the hormone receptor or coupling of the receptor to the stimulatory guanine nucleotide regulatory subunit (Gs). The results demonstrate that bradykinin stimulates phospholipase C leading to activation of protein kinase C, which then inhibits vasopressin-stimulated cAMP production at the level of the hormone receptor or coupling of the receptor to Gs in cultured cortical collecting tubular cells.
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PMID:Bradykinin activates protein kinase C in cultured cortical collecting tubular cells. 255 39

The binding of vasopressin, angiotensin II and prazosin (alpha 1-adrenergic antagonist) to purified heavy (GH) and (intermediate + light) (GI + L) rat liver Golgi fractions was studied. The three types of ligands showed a saturable and specific binding in Golgi fractions; the maximal specific binding of [3H]vasopressin, [3H]prazosin and [125I]Sar-N3-Phe-angiotensin II was respectively 5-10%, 20-30% and 30-40% of that detected in purified plasma membranes. The apparent binding affinities of the three ligands were the same whether determined in Golgi fractions or plasma membranes. The presence of vasopressin, alpha 1-adrenergic and angiotensin receptors in very different proportions, as compared to the amount of receptor detected in plasma membranes, in GH and GI + L Golgi fractions was not compatible with the idea that a plasma membrane impurity accounted for the detection of receptor in the purified intracellular particulate fractions. In vivo injection of [125I]Sar-N3-Phe-angiotensin II resulted in a receptor-mediated endocytosis of the iodo-angiotensin analog into the GH and GI + L Golgi fractions. The apparent molecular weight of the irreversible complex, [125I]angiotensin-receptor, was estimated in subcellular fractions using SDS-PAGE electrophoresis. This value was identical after either in vivo or in vitro labelling (MW = 63,000) and was indistinguishable from the molecular weight of the irreversible hormone receptor complex present in the plasma membranes.
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PMID:Vasopressin, angiotensin and adrenergic receptors of rat liver Golgi fractions--molecular weight of the angiotensin-receptor irreversible complex after in vitro and in vivo labelling. 295 70

The urinary bladder of the toad Bufo marinus has been used to examine the effect on sodium transport, measured by short-circuit current, of natural antidiuretic hormones and several synthetic peptide analogs. In mammals, these synthetic analogs show specificity for different receptors, designated V1 and V2 receptors, whose biological responses are mediated by phosphatidyl inositol breakdown products or adenylate cyclase activity, respectively. All analogs stimulated SCC, with relative potencies AVT greater than AVP greater than Phe2 OVT (V1 agonist) much greater than d(CH2)5Tyr(Me)AVP (V1 antagonist) = d(CH2)5[D-Ile2,Abu4]AVP (V2 antagonist). The V1 and V2 antagonists inhibited the SCC response to AVT and Phe2OVT, with similar inhibitory potencies. We conclude that the stimulation of sodium transport by antidiuretic hormones involves one hormone receptor which does not show the selectivity of mammalian antidiuretic hormone receptors, and may represent a more primitive type of receptor.
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PMID:Response of toad urinary bladder to vasopressin analogs possessing V1 or V2 specificity. 296 74


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