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 new solid-phase extraction method using octyl-silica columns to extract vasopressin-like immunoreactivity from plasma has been developed. The extraction was followed by a radioimmunoassay on the vacuum-dried extracts, which were reconstituted in assay buffer. The total recovery of synthetic vasopressin was ca. 100%. Based on co-elution with synthetic vasopressin after separation by reversed-phase high-performance liquid chromatography of plasma extracts from normal Wistar and Brattleboro rats, and the cross-reactivity of the antiserum used in the radioimmunoassay system, the extracted material was found to be indistinguishable from authentic vasopressin. Unknown experimental samples were interpolated on a standard curve established in "zero" plasma (plasma derived from rats subjected to waterload) spiked with known amounts of synthetic vasopressin, and not on a standard curve established in assay buffer. The limit of detection was 1 fmol of vasopressin equivalent per millilitre. The intra- and inter-assay coefficients of variance were 10-16% and 16%, respectively. The procedure reliably showed that osmotic challenge and 24-h dehydration increased, whereas ethanol ingestion decreased vasopressin-like immunoreactivity plasma levels in the rat, compared with normally hydrated controls.
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PMID:Solid-phase extraction of plasma vasopressin: evaluation, validation and application. 187 64

The hydrodynamic behavior of G alpha s, the alpha subunit of the stimulatory guanine nucleotide-binding regulatory protein (G protein), in octyl glucoside extracts of rat liver membranes was investigated. As was previously shown for G proteins similarly extracted from brain synaptoneurosomes, G alpha s behaved as polydisperse structures with S values higher than that of heterotrimeric G proteins. At concentrations of guanosine 5'-[gamma-thio]triphosphate (GTP[gamma S]) greater than 100 microM, incubation with membranes led to smaller structures having S values in the range of 4-5 S. Incubation of liver membranes with glucagon also caused a marked increase in structures having these S values; glucagon action required the presence of low concentrations of GTP[gamma S] (maximal, 10 microM), was rapid (within 10 sec), and was not observed with vasopressin, angiotensin II, or glucagon-(19-29). When G alpha s in its membrane-bound form was [32P]ADP-ribosylated by cholera toxin and the treated membranes were extracted with octyl glucoside, greater than 35% of the labeled G alpha s was found in material that sedimented through sucrose gradients and contained relatively low levels of immunoreactive G alpha s. Glucagon selectively converted the apparently large molecular weight structures to the 4-5 S structures in the presence of GTP[gamma S], even at 1 mM (the maximal effect of the nucleotide alone), when incubated with the toxin-treated membranes. These findings suggest that the glucagon receptor selectively interacts with polymer-like structures of G alpha s and that activation by GTP[gamma S] results in disaggregation. The role of the beta and gamma subunits of G proteins in the hormone-induced process is not clear since the polymer-like structures extracted with octyl glucoside are devoid of beta and gamma subunits.
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PMID:Glucagon induces disaggregation of polymer-like structures of the alpha subunit of the stimulatory G protein in liver membranes. 190 89

Intracellular Ca (Cai) is an inhibitory second messenger in renin secretion, and it has been hypothesized that some first messengers--especially angiotensin II [A-II] and antidiuretic hormone [ADH], and possibly A1-adenosine receptor antagonists as well--increase Cai and thereby inhibit renin secretion by causing the release or mobilization of Ca from intracellular sites of sequestration. The present experiments were designed to test this hypothesis, by using 3,4,5-trimethoxybenzoic acid 8-(diethylamino)-octyl ester (TMB-8), a putative antagonist of Ca release from intracellular sequestration sites. The rat renal cortical slices preparation was used. Basal renin secretory rate was unaffected by 1 and 10 microM TMB-8, but more than doubled in response to 100 microM TMB-8. Basal renin secretory rate was inhibited by A-II (1 microM), by ADH (200 units/1), by an A1-adenosine receptor agonist (N6-cyclohexyladenosine, or CHA; 0.5 microM), and by an alpha-adrenergic agonist (methoxamine; 10 microM). Only the inhibitory effect of methoxamine was blocked by 1 and 10 microM TMB-8, but these concentrations had no effect on basal secretory rate. At 100 microM, TMB-8 blocked the inhibitory effects of ADH as well as of methoxamine, but failed to block the inhibitory effects of CHA and A-II. However, these observations cannot be taken as evidence that methoxamine and ADH, but not CHA and A-II, inhibit renin secretion by a mechanism involving release of Ca from intracellular sequestration sites, because 100 microM TMB-8 clearly had non-specific effects. Among them, it completely blocked the inhibitory effect of K-depolarization on renin secretion. Collectively, at least three separate actions of TMB-8 must be invoked to explain the present results. Likely candidates are an Na-channel blocking effect and a Ca channel blocking effect in addition to antagonism of the release of Cai.
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PMID:Calcium-dependent inhibition of renin secretion: TMB-8 is a non-specific antagonist. 192 44

Previous studies have shown that vascular endothelial cells exhibit a highly active Na-K-Cl cotransport system that is regulated by a variety of vasoactive hormones and neurotransmitters, suggesting that the cotransporter may play an important role in endothelial cell function. In this study, the regulation of endothelial cell Na-K-Cl cotransport was further investigated by probing the stimulus-transfer pathway by which vasoactive agents stimulate the cotransporter. Specifically, three peptides previously shown to stimulate cotransport activity (angiotensin II, vasopressin, and bradykinin) were evaluated. Na-K-Cl cotransport was assessed in cultured bovine aortic endothelial cells as bumetanide-sensitive K+ influx. Stimulation of Na-K-Cl cotransport by angiotensin II, vasopressin, or bradykinin was found to be reduced either by removal of extracellular Ca2+ or by treatment of the cells with 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate or 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid. In addition, the calmodulin antagonist W-7 was found to prevent stimulation of endothelial cell Na-K-Cl cotransport by the three peptides. These findings suggest that regulation of endothelial cell cotransport by these vasoactive peptides may be both Ca(2+)- and calmodulin-dependent. Angiotensin II, vasopressin, and bradykinin were also found to elevate phosphatidylinositol hydrolysis in the cultured endothelial cells. Thus, the possibility that regulation of endothelial Na-K-Cl cotransport by these vasoactive peptides also involves diacylglycerol activation of protein kinase C was investigated. A 10-min exposure of the endothelial cells to low doses of phorbol 12-myristate 13-acetate was found to reduce Na-K-Cl cotransport whether in the presence or absence of angiotensin II, vasopressin, or bradykinin. However, down-regulation of protein kinase C by a 40-h exposure to higher doses of the phorbol ester was found to elevate Na-K-Cl cotransport activity under both control and agonist-stimulated conditions, indicating that activation of protein kinase C results in inhibition of endothelial cell Na-K-Cl cotransport. Thus, protein kinase C activation may serve as negative feedback in the stimulus-transfer pathway by which these agonists regulate endothelial cell Na-K-Cl cotransport.
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PMID:Endothelial cell sodium-potassium-chloride cotransport. Evidence of regulation by Ca2+ and protein kinase C. 205 Jun 66

The apical plasma membrane of epithelial cells of frog and toad urinary bladder is subject to large modifications during the induction of water permeability by the antidiuretic hormone. A better characterization of the apical membrane is necessary for a clear understanding of the mechanisms of hormone action. Towards this end, apical material was extracted by enzymatic treatment and by incubation with detergent. Proteolytic enzyme alone had little effect under our conditions. A pretreatment with several glycosidases (alpha-mannosidase or endo-beta-N-acetylglucosaminidase H) increased the hydrolytic action of papain, elastase, proteinase K or Staphylococcus aureus V8 protease and allowed the detection of a major 76 kD in SDS gel electrophoresis. The n-octyl-beta-D-glucopyranoside (0.2%) led to the extraction after 150 mn of 1 to 5 micrograms proteins per cm2 of amphibian urinary bladder apical surface. The extracted proteins migrated as several bands on SDS gels. One of them probably corresponds to the 76 kD fragment obtained after proteolysis. The absence of alteration of the water permeability after extraction and the good preservation of the ultrastructure are evidence for the localisation of the 76 kD at the apical membrane surface. This protein may be the best candidate as antigen to raise antibodies against the apical surface of amphibian urinary bladder epithelial cells.
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PMID:Apical material extracted from amphibian urinary bladder epithelium by enzymes and detergent treatment. 293 6

Arginine vasopressin (AVP) binds specifically to vascular smooth muscle-like mesangial cells (MCs) and affects contraction. We tested whether this peptide also modulates growth behavior of rat MCs in early subculture (passage 2-5). Subconfluent, serum-starved MCs were exposed to AVP (10(-10)-10(-6) M) in the presence or absence of insulin (5 micrograms/ml). To assess DNA replication, MC uptake of [3H]thymidine (24-h pulse) was determined on days 1, 2, and 3. AVP alone averaged a 1.97-fold increase in DNA synthesis at 24 h, whereas the mean stimulatory effects of AVP at 48 and 72 h were 7.21- and 5.42-fold, respectively. MCs exposed simultaneously to AVP and insulin showed potentiation of the mitogenic response to AVP alone. The V1-receptor antagonist [1-(beta-mercapto-beta,beta-cyclopentamethylene proprionic acid), 2-(O-methyl-Tyr)-Arg]vasopressin (PMP) inhibited only AVP-induced promotion of MC growth (maximal inhibition of -78.3%). The phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA) acutely stimulated MC proliferation but did not add to the AVP effect. Preincubation of MCs with 600 nM of TPA for 48 h significantly inhibited AVP-induced mitogenesis (-87.2%). By use of fura-2, intracellular calcium (Cai) was assessed by spectrofluorometry. The addition of AVP (10(-12)-10(-6) M) led to a rapid, transient, dose-dependent increase in Cai of 154-383%, respectively. The AVP-induced increase in Cai was greatly inhibited by 3,4,5-trimethoxybenzoic acid 8-(diethylamino)octyl ester hydrochloride (TMB-8) (10(-8)-10(-6) M), an inhibitor of Cai release (-23.9 to -72.1%), and it was blunted by the atrial natriuretic peptide AP-28 (-38.3%).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Arginine vasopressin promotes growth of rat glomerular mesangial cells in culture. 297 44

Mitogenic stimulation of quiescent human fibroblasts (HSWP) with a growth factor mixture (consisting of epidermal growth factor (EGF), insulin, bradykinin, and vasopressin) rapidly induces an increase in Na influx via a Ca-mediated activation of an amiloride-sensitive Na/H exchanger. Inositol phosphates (specifically inositol-1',4',5'-phosphate) have been implicated in mediating the mobilization of intracellular Ca stores in other cell types and we have now completed a detailed analysis of the mitogen-induced release of inositol phosphates in HSWP cells. Stimulation of inositol trisphosphate release is rapid (within 5 s) and reaches a maximum level (416-485% basal) within 10-15 s after the addition of growth factor mixture. Inositol bisphosphate and inositol monophosphate reach maximum levels by 30 s (1257% basal) and 60 s (291% basal), respectively. Levels of all three compounds then decay toward basal levels but remain elevated (150-350% of basal levels) after 10 min of incubation with mitogens. The effects of different combinations of these growth factors and of the bee venom peptide, melittin, have also been determined. We have also found that 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate, which prevents the mitogen-induced rise in intracellular calcium activity and activation of Na influx, does not alter the mitogen-stimulated accumulation of inositol trisphosphate. In addition, the calcium ionophore A23187, which increases cytosolic Ca activity and induces a Na influx, does not stimulate the release of inositol trisphosphate. Assays performed in the presence of lithium, which inhibits inositol phosphate monophosphatase, promotes the prolonged and enhanced accumulation of inositol monophosphate. Treatment with the phospholipase inhibitor mepacrine or pretreatment with dexamethasone reduces the amount of inositol phosphates released upon mitogenic stimulation. Hence mitogenic stimulation of HSWP cells leads to the rapid stimulation of inositol phosphate release via a calcium-independent mechanism and suggests inositol trisphosphate as a candidate to mediate the release of intracellular calcium stores which is involved in the processes responsible for the activation of the Na/H exchanger.
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PMID:Mitogen-stimulated release of inositol phosphates in human fibroblasts. 302 68

Vasopressin and angiotensin II inhibited in a dose-dependent fashion the stimulation of ureagenesis induced by alpha 1-adrenergic activation in hepatocytes incubated in medium without calcium and containing 25 microM EGTA. Vasopressin was more potent than angiotensin II. The effect of different inhibitors of protein kinase C on the alpha 1-adrenergic blockade induced by the vasopressor peptides was tested. It was observed that N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide (W-7), 4-aminoethyl-1-[2,3-bis(n-decloxyl)-n-propyl]-4-phenylpiperadin e dihydrochloride (CP-46,665-1); 8-(N,N-diethylamino)octyl-3,4, 5-trimethoxybenzoate (TMB-8), polymyxin B and 1-(5-isoquinolynsulfonyl)-2-methylpiperazine (H-7) block this effect of the vasopressor peptides in a dose-dependent fashion. The active phorbol ester, phorbol 12-myristate 13-acetate (PMA), also inhibited the alpha 1-adrenergic stimulation of ureagenesis in these cells. The inhibitors of protein kinase also blocked the effect of phorbol esters but a preincubation with the inhibitors before the addition of PMA was required. alpha 1-Adrenergic activation of phosphatidylinositol labeling was also abolished by PMA; the inhibitors of protein kinase partially blocked this effect of PMA. In summary, our data indicate that inhibitors of protein kinase C can block the alpha 1-adrenergic refractoriness induced by active phorbol esters, vasopressin and angiotensin II. The data are consistent with an important role of protein kinase C in modulating the alpha 1-adrenergic responsiveness of hepatocytes.
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PMID:Inhibitors of protein kinase C block the alpha 1-adrenergic refractoriness induced by phorbol 12-myristate 13-acetate, vasopressin and angiotensin II. 302 3

Previous studies have shown that hypertonic mannitol or NaCl increases the release of [3H]arachidonate and immunoreactive prostaglandin E in inner medullary slices incubated in Ca2+-free media containing EGTA. By contrast, the stimulation of these parameters by ionophore A23187 and by arginine-vasopressin are abolished in Ca2+-free media plus EGTA. In the present study, the effects of Ca2+ deprivation and the intracellular Ca2+ antagonist TMB-8 [8-N,N-diethylamino)octyl-3,4,5 -trimethoxybenzoate-HCl) were further examined to assess the Ca2+ dependence of the actions of different stimuli of prostaglandin E synthesis in rat renal inner medulla. Ca2+-free media without EGTA abolished increases in [3H]arachidonate and immunoreactive prostaglandin E release induced by ionophore A23187, but not those induced by arginine-vasopressin, suggesting that different pools of Ca2+ subserve expression of the actions of these two stimuli. At low concentrations, TMB-8 (10-25 microM) inhibited increases in [3H]arachidonate and immunoreactive prostaglandin E release induced by arginine-vasopressin, but did not influence effects of Ca2+ plus ionophore A23187 or hypertonicity on these parameters. At higher concentrations (100-500 microM), TMB-8 suppressed effects of ionophore A23187, hyperosmolar NaCl and mannitol on immunoreactive prostaglandin E and [3H]arachidonate release from slices. The effects of a sub-optimal inhibitory concentration of TMB-8 on ionophore A23187 actions were overcome by increasing Ca2+ in the media from 1.5 to 5 mM. Ca2+ deprivation, or concentrations of EGTA or TMB-8, that were effective in suppressing increases in immunoreactive prostaglandin E induced by ionophore A23187, arginine-vasopressin or hypertonicity, did not modify increases in immunoreactive prostaglandin E induced by exogenous arachidonate. Moreover, in microsomal fractions of inner medulla, TMB-8 suppressed Ca2+-dependent increases in phospholipase A2 and C activities, an effect which was competitive with Ca2+. Thus, Ca2+ deprivation and TMB-8 act at a step in the immunoreactive prostaglandin E synthetic pathway proximal to cyclooxygenase activity, and probably at the level of Ca2+-dependent acyl hydrolase activity. The results with TMB-8 indicate that an intracellular pool of Ca2+ is involved in expression of the actions of hypertonicity to increase [3H]arachidonate release and immunoreactive prostaglandin E in inner medulla.
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PMID:Calcium dependence of the stimulatory action of hypertonicity on renal medullary prostaglandin synthesis. 623 60

The solubilization of vasopressin receptors from plasma membranes of bovine kidney and rat liver by different detergents was investigated. A prerequisite for the extraction of vasopressin receptors retaining binding affinity for their ligand was the stabilization of the receptors by the prior formation of the membrane-bound hormone-receptor complexes. The vasopressin-receptor complexes from both kidney and liver membranes were solubilized in a high yield with dodecyl-beta-D-maltoside and 3-laurylamido-N,N'-dimethylpropylaminoxide. Several other nonionic detergents including octyl-beta-D-glucopyranoside effectively extracted the hepatic vasopressin receptor. For the hormone-receptor complex solubilized from bovine kidney with dodecyl-beta-D-maltoside, a Stokes' radius of 5.8 nm was determined.
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PMID:Solubilization of ligand-stabilized vasopressin receptors from plasma membranes of bovine kidney and rat liver. 631 12


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