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 mechanism by which vasopressin enhances phospholipase A2 activation in rabbit platelets was investigated. Stimulation of the platelets with vasopressin enhanced arachidonic acid liberation, as well as aggregation and ATP secretion in the presence of submaximal concentration of A23187, although vasopressin alone had no effect. The vasopressin-enhanced liberation was inhibited by p-bromophenacyl bromide, a phospholipase A2 inhibitor, and by genistein, a tyrosine kinase inhibitor. Though epinephrine also caused a similar enhancement of the liberation, this effect of epinephrine was insensitive to genistein. Staurosporine, a protein kinase C inhibitor, completely suppressed phorbol 12-myristate 13-acetate-enhanced arachidonic acid liberation, but suppressed the vasopressin-induced enhancement only slightly. These results suggest that vasopressin-enhanced phospholipase A2 activation may be regulated by a genistein-sensitive mechanism, most likely by a protein tyrosine kinase-mediated pathway, but not by guanine nucleotide-binding protein- or protein kinase C-mediated pathway.
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PMID:Enhancement of A23187-induced arachidonic acid liberation by vasopressin is sensitive to genistein in rabbit platelets. 826 Sep 37

Arginine vasopressin (AVP) induced concentration-dependent (10(-9) to 10(-6) M) stimulation of inositol phosphate production and a biphasic increment of cytosolic free Ca2+ concentration ([Ca2+]i) in skeletal myogenic cells in culture. These effects were almost completely abolished when the cells were pretreated with the AVP antagonist [deamino-Pen1,Val4,D-Arg8]-vasopressin before stimulation with AVP, thus confirming a V1 receptor-mediated effect. Inositol 1,4,5-trisphosphate production was maximally stimulated within 2-3 s of treatment with AVP, immediately followed by release of Ca2+ from intracellular deposits. Both effects were inhibited by treatment with 12-O-tetradecanoyl phorbol 13-acetate (TPA). Such effect of TPA was reversed by the protein kinase C inhibitor staurosporine. Vasopressin also regulated the intracellular pH of responsive cells with mechanisms involving both Na+ and anion transport across the plasma membrane. However, unlike in other cell types, AVP stimulated the Na(+)-H+ antiport only simultaneously with a dramatic cell acidification or after treatment with TPA. Response to AVP was observed in L6 and L5 and, to a lesser extent, in chick embryo myogenic cells, regardless of the stage of differentiation (myoblast or myotube). Comparison of different subclones of the L6 cell line demonstrated that the responsiveness to AVP correlated positively with their myogenic potential.
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PMID:Transduction of arginine vasopressin signal in skeletal myogenic cells. 839 77

Of nine biological factors (ATP, bradykinin, vasopressin, substance P, angiotensin II, norepinephrine, epinephrine, 12-tetradecanoylphorbol 13-acetate (TPA), and A23187 calcium ionophore) examined, bradykinin, as well as ATP, TPA, and A23187, significantly increased the phosphorylation of epidermal growth factor (EGF) receptors and reduced the binding of EGF to their high-affinity site. The reduction in EGF binding by bradykinin, ATP, and TPA was similarly reversed by concomitant incubation with staurosporine, a protein kinase C inhibitor, implying that the phosphorylation of EGF receptors was catalyzed probably by a protein kinase C of the same or similar type in each case. This possibility was confirmed by the fact that the major phosphorylation site of EGF receptors by the stimulation with either bradykinin, ATP, or TPA was the same (Thr-654). Different from the stimulations with ATP and TPA, the effect of bradykinin of decreasing the high-affinity EGF binding was transient (a minimum binding at 2.5 min); the reduced EGF binding was, however, sustained for up to 30 min in the presence of calyculin A, a phosphoprotein phosphatase inhibitor. Moreover, the homogenate prepared from bradykinin-stimulated A-431 cells had stronger dephosphorylation activity for phosphorylated EGF receptors than that from control cells. These results suggest that bradykinin stimulates both the protein kinase C system and a phosphoprotein phosphatase(s) activity in A-431 cells. Such biphasic effects of bradykinin to phosphorylate and dephosphorylate EGF receptors via protein kinase C and a phosphoprotein phosphatase, respectively, imply a homeostatic control of receptor function in regulating phosphorylation level by the same bioactive factor.
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PMID:Bradykinin-stimulated transient modulation of epidermal growth factor receptors in A-431 human epidermoid carcinoma cells. 840 28

Vasoactive peptides mobilize cytosolic free Mg2+ in vascular smooth muscle cells. It is unknown whether angiotensin II and arginine vasopressin, potent vasoconstrictor agents, influence intracellular Mg2+. The effects of angiotensin II and vasopressin on intracellular free Mg2+ concentrations ([Mg2+]i) were therefore investigated in primary cultured unpassaged vascular smooth muscle cells (VSMC) from mesenteric arteries of Wistar Kyoto rats, and in an established cell line of rat thoracic aorta cells (A10 cells). Underlying mechanisms of agonist-stimulated [Mg2+]i changes were assessed in A10 cells by pharmacologically manipulating phospholipase C, protein kinase C, and the Na+/H+ exchanger. In addition, the dependence of [Mg2+]i on intracellular Ca2+ was determined. [Mg2+]i was measured in single cells by fluorescent digital imaging using mag-fura-2/AM. Basal [Mg2+]i levels in Wistar Kyoto rat and A10 cells were 0.62 +/- 0.02 mmol/liter and 0.58 +/- 0.01 mmol/liter, respectively. Angiotensin II and vasopressin induced a dose-dependent biphasic [Mg2+]i response where [Mg2+]i increased rapidly and transiently to a peak level and then declined to subbasal levels, which were sustained. Preexposure of cells to neomycin, a nonspecific phospholipase C inhibitor, U-73122, a selective phospholipase C inhibitor, calphostin C, a selective protein kinase C inhibitor, and 5-(N, N-hexamethylene)amiloride, a selective Na+/H+ exchange blocker, attenuated angiotensin II- and vasopressin-induced [Mg2+]i responses in a concentration-dependent manner. Removal of extracellular Na+ completely inhibited agonist-elicited [Mg2+]i transients. To determine whether intracellular free Ca2+ concentration ([Ca2+]i) influences agonist-induced [Mg2+]i changes, thapsigargin, a selective sarcoplasmic reticular Ca2+-ATPase inhibitor, was used to deplete intracellular Ca2+ stores. In thapsigargin-pretreated cells, angiotensin II-elicited [Ca2+]i responses were significantly attenuated, whereas agonist-induced [Mg2+]i responses were unchanged. These data demonstrate that in primary cultured VSMC and in an established VSMC line, angiotensin II and vasopressin modulate [Mg2+]i through receptor-mediated pathways, which are [Ca2+]i-independent but which involve phospholipase C, protein kinase C, and the Na+/H+ exchanger. These pathways are linked to a Na+-dependent Mg2+ transporter, which facilitates transmembrane Mg2+ transport.
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PMID:Angiotensin II and vasopressin modulate intracellular free magnesium in vascular smooth muscle cells through Na+-dependent protein kinase C pathways. 879 89

Epidermal growth factor (EGF) and insulin induced similar effects in isolated rat adipocytes. To determine whether EGF and insulin produced similar effects through the same mechanisms, we focused on lipolysis. Insulin inhibited the lipolysis stimulated by isoproterenol, glucagon (either alone or in combination with adenosine deaminase), adenosine deaminase itself, or forskolin. In contrast, EGF did not inhibit the lipolysis stimulated by forskolin or by hormones when the cells were also incubated with adenosine deaminase. The effect of insulin, but not that of EGF, on isoproterenol-stimulated lipolysis disappeared when adipocytes were incubated with 1 microM wortmannin. These results indicate that EGF and insulin affected lipolysis through different mechanisms. We observed that EGF, but not insulin, increased cytosolic Ca2+. The effect of EGF, but not that of insulin, disappeared when the cells were incubated in a Ca2+-free medium. We suggest that EGF, but not insulin, mediate its antilipolytic effect through a Ca2+-dependent mechanism which, however, do not involve Ca2+-activated protein kinase C isoforms. This is based on the following: 1) phorbol 12-myristate 13-acetate affected lipolysis in an opposite way to that of EGF; and 2) the protein kinase C inhibitor bisindolylmaleimide GF 109203X did not affect the antilipolytic action of EGF. Our results indicate that the antilipolytic effect of EGF resembles more that of vasopressin than that of insulin.
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PMID:The antilipolytic effects of insulin and epidermal growth factor in rat adipocytes are mediated by different mechanisms. 882 75

The purpose of this study was to investigate the effects of arginine vasopressin (AVP) on nitric oxide (NO) synthesis in vascular smooth muscle cells (VSMCs). We measured the production of nitrite, a stable metabolite of NO, and the expression of inducible NO synthase (iNOS) mRNA in cultured rat VSMCs. Incubation of VSMCs for 24 h with interleukin-1 beta (IL-1 beta) caused a significant increase in NO production. Both AVP and the V1a receptor agonist [Phe2, Ile3, Orn8]vasopressin inhibited NO synthesis in IL-1 beta-stimulated cells, but not in unstimulated cells, in a dose-dependent manner. The V1a receptor antagonist [d(CH2)5(1), O-Me-Tyr2, Arg8]vasopressin completely inhibited the effect of AVP. Incubation with IL-1 beta for 24 h induced the expression of iNOS mRNA in VSMCs, while AVP suppressed its expression. After functional depletion of protein kinase C activity by treating cells with phorbol 12-myristate 13-acetate for 24 h, AVP did not inhibit IL-1 beta-induced NO production. The effect of AVP was also inhibited in the presence of the protein kinase C inhibitor calphostin C in a dose-dependent manner. These results indicate that AVP inhibits IL-1 beta-induced iNOS expression in VSMCs through the V1a receptor, which is mediated at least partially via activation of protein kinase C.
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PMID:Arginine vasopressin inhibits nitric oxide synthesis in cytokine-stimulated vascular smooth muscle cells. 932 2

We investigated the effects of arginine vasopressin (AVP) on nitric oxide (NO) synthase activity in cardiac myocytes by measuring the production of nitrite, a stable metabolite of NO, and the expression of inducible NO synthase (iNOS) mRNA and protein. Incubation of cultured neonatal rat cardiac myocytes for 24 hours with interleukin-1beta (IL-1beta) caused a significant increase in NO production. Both AVP and V1a receptor agonist [Phe2,Ile3,Orn8]vasopressin augmented NO synthesis in IL-1beta-stimulated, but not in unstimulated myocytes, in a dose-dependent manner. The V1a receptor antagonist [d(CH2)[5]1,O-Me-Tyr2,Arg8]vasopressin completely inhibited the effect of AVP. The AVP-induced NO production by IL-1beta-stimulated cells was accompanied by increased iNOS mRNA and protein accumulation. AVP caused a significant increase in cytosolic free Ca2+ levels of cardiac myocytes, whereas it showed no effect on cytosolic cAMP levels. After protein kinase C activity was functionally depleted by treating cells with phorbol 12-myristate 13-acetate for 24 hours, AVP did not augment IL-1beta-induced NO production. The effect of AVP was also inhibited in the presence of the protein kinase C inhibitor calphostin C. The addition of AVP increased protein kinase C activity in cardiac myocytes, and its effect was significantly inhibited in the presence of calphostin C. These results support the hypothesis that the heart may be a target organ for AVP and that AVP modulates IL-1beta-induced iNOS expression in myocytes through the V1a receptor, which is mediated at least partially via activation of protein kinase C.
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PMID:Arginine vasopressin increases nitric oxide synthesis in cytokine-stimulated rat cardiac myocytes. 936 64

The G protein-coupled m1 and m3 muscarinic acetylcholine receptors increase tyrosine phosphorylation of several proteins, including the focal adhesion-associated proteins paxillin and focal adhesion kinase (FAK), but the mechanism is not understood. Activation of integrins during adhesion of cells to extracellular matrix, or stimulation of quiescent cell monolayers with G protein-coupled receptor ligands including bradykinin, bombesin, endothelin, vasopressin, and lysophosphatidic acid, also induces tyrosine phosphorylation of paxillin and FAK and formation of focal adhesions. These effects are generally independent of protein kinase C but are inhibited by agents that prevent cytoskeletal assembly or block activation of the small molecular weight G protein Rho. This report demonstrates that tyrosine phosphorylation of paxillin and FAK elicited by stimulation of muscarinic m3 receptors with the acetylcholine analog carbachol is inhibited by soluble peptides containing the arginine-glycine-aspartate motif (the recognition site for integrins found in adhesion proteins such as fibronectin) but is unaffected by peptides containing the inactive sequence arginine-glycine-glutamate. Tyrosine phosphorylation elicited by carbachol, but not by cell adhesion to fibronectin, is reduced by the protein kinase C inhibitor GF 109203X. The response to carbachol is dependent on the presence of fibronectin. Moreover, immunofluorescence studies show that carbachol treatment induces formation of stress fibers and focal adhesions. These results suggest that muscarinic receptor stimulation activates integrins via a protein kinase C-dependent mechanism. The activated integrins transmit a signal into the cell's interior leading to tyrosine phosphorylation of paxillin and FAK. This represents a novel mechanism for regulation of tyrosine phosphorylation by muscarinic receptors.
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PMID:Tyrosine phosphorylation of paxillin and focal adhesion kinase by activation of muscarinic m3 receptors is dependent on integrin engagement by the extracellular matrix. 963 40

The effect of activation of the Ca2+-sensing receptor on net Cl flux (JCl) has been investigated on microperfused cortical (C) thick ascending limb (TAL) from rat kidney. Increasing bath Ca2+ from 0.5 to 3 mM or adding 200 microM of the specific Ca2+-sensing receptor agonist neomycin reduced basal as well as antidiuretic hormone (ADH)-stimulated JCl by 27.7 +/- 5.0% and 25.9 +/- 4.1%, respectively. JCl remained unchanged in time control tubules. The effect of neomycin/Ca2+ on JCl was blocked by two protein kinase A inhibitors, H-9 or H-89, but not by a protein kinase C inhibitor, GF-109203X, regardless of whether ADH was present or not. Moreover, H-89 decreased basal JCl and prevented a further effect of 3 mM Ca2+. When JCl was increased by 8-bromo-cAMP plus IBMX, no effect of 3 mM Ca2+ was observed. Inhibitors of phospholipase A2 and cytochrome P-450 monooxygenase failed to modify the effect of 3 mM Ca2+, although these agents dampened significantly the inhibitory effect of bradykinin on medullary TAL. We conclude that extracellular Ca2+ decreases basal and ADH-stimulated Cl reabsorption in CTAL by inhibiting the cAMP pathway, independently of protein kinase C or phospholipase A2 stimulation.
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PMID:Extracellular Ca2+ decreases chloride reabsorption in rat CTAL by inhibiting cAMP pathway. 969 Oct 8

The A1 catecholamine neurons of the caudal ventrolateral medulla transmit hemodynamic information to the vasopressin (VP) neurons in the hypothalamus. These neurons corelease ATP with norepinephrine. Perifused explants of the hypothalamoneurohypophyseal system were used to investigate the role of these substances on VP release. ATP (100 micrometer) increased VP release 1.5-fold (p = 0.027). The response was rapid but unsustained. It was blocked by the P(2) receptor antagonist pyridoxal-phosphate-6-azophenyl-2',4'-disulphonic acid (PPADS). The alpha(1)-adrenergic agonist phenylephrine (PE; 100 micrometer) also increased VP release by 1.5-fold (p = 0.014). Again, the response was rapid and unsustained. However, simultaneous perifusion of explants with ATP (100 micrometer) and PE (100 micrometer) resulted in a threefold to fourfold increase in VP release, which was sustained for as long as 4 hr. There was a similar synergistic effect of ATP and PE on oxytocin release. Interestingly, the synergistic response was delayed approximately 40 min relative to the response to either agent alone. Several experiments were performed to elucidate the cellular mechanisms of this synergism. The effect was blocked by PPADS, a protein kinase C inhibitor (bisindolylmaleimide I HCl), and actinomycin, an inhibitor of gene transcription. These data suggest that P(2X) receptor activation, PKC-mediated phosphorylation, and gene transcription are required for the synergistic response. The marked synergism of these coreleased agents is probably important to achieve sustained increases in plasma VP in response to prolonged hypotension. These observations may also have broad applications to CNS function, because ATP may be coreleased at noradrenergic synapses throughout the CNS.
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PMID:Purinergic and adrenergic agonists synergize in stimulating vasopressin and oxytocin release. 1110 96


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