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)

Low doses of apomorphine (20-50 micrograms/kg) induced an increase in the activity of an endogenous inhibitor of cAMP dependent protein Kinases (type I inhibitor) in the striatum, anterior and posterior hypothalamus of normotensive rats by stimulating D2-dopamine receptors. In contrast, high doses of the compound (2-10 mg/kg) produced a dose dependent decrease in type I inhibitor activity. In the posterior hypothalamus of vasopressin hypertensive rats and SHR the maximal increase of type I inhibitor activity was markedly higher than in normotensive animals. Moreover, apomorphine induced the increase of type I inhibitor activity in a much wider range of doses. Only as high dose of the compound as 10 mg/kg was able to decrease type I inhibitor activity. This points to a marked supersensitivity of D2 receptors and suggests the subsensitivity of D1 receptors in this brain area of hypertensive rats. In contrast, in the striatum and anterior hypothalamus of hypertensive rats the apomorphine dose response curves were similar to those in normotensive rats. Thus, it seems tha hypertension is associated with the alteration in sensitivity of D2 and D1 receptors in the posterior hypothalamus, the brain area involved in regulation of blood pressure.
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PMID:The responsiveness of D1- and D2-dopamine receptors in the striatum and hypothalamus of spontaneous and vasopressin hypertensive rats. 128 99

A large Mg2+ cell uptake against concentration gradients is stimulated in collagenase-dispersed rat myocytes by carbachol and in hepatocytes by carbachol or vasopressin. The signalling pathway(s) responsible for this stimulation of Mg2+ uptake was investigated by using various activators or inhibitors of protein kinase C (PKC) and by correlating Mg2+ uptake with cell PKC activity and cAMP content. In both cell preparations, the direct stimulation of PKC by diacylglycerol analogs or phorbol esters reproduce the same pattern of Mg2+ uptake as that induced by carbachol or vasopressin. These data indicate that the activation of PKC is responsible for a stimulation of Mg2+ uptake by myocytes or hepatocytes, whereas increase in cAMP in these cells stimulates Mg2+ release.
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PMID:Regulation of Mg2+ uptake in isolated rat myocytes and hepatocytes by protein kinase C. 131 Feb 87

The murine receptor for luteinizing hormone (LHR) was cloned and expressed in L cells. This LHR (mature protein of 674 amino acids) is very similar to that of the rat (same length, 36 amino acid differences) but differs significantly more from that of man (673 amino acids, 109 differences). Expression of the murine LHR in L cells led to the appearance of binding sites for human chorionic gonadotropin (hCG) with a Kd of 150 pM and an LH- and hCG-stimulable adenylyl cyclase activity (EC50 = 50-100 pM hCG). Upon labeling pools of phosphoinositides with [3H]myo-inositol, L cells expressing the murine LHR responded to hCG with an increase in their rate of phosphoinositide hydrolysis (EC50 = 2,400 pM hCG). This was accompanied by an increase in intracellular Ca2+ [( Ca2+]i), as determined by the Fura2 method. This increase in [Ca2+]i in response to hCG was dependent on the LHR, for HCG did not affect [Ca2+]i in L cells not expressing the LHR. The effect was not due to the cAMP-forming activity of the LH receptor, for neither forskolin nor prostaglandin E1, which both increase cAMP levels in L cells, had a similar effect in either control or LHR-expressing cells and isoproterenol had no effect in L cells expressing a functionally active hamster beta-adrenergic receptor. The effect was also not due to overexpression of a Gs-coupled receptor, for L cells expressing 8-fold higher levels of the human V2 vasopressin receptor did not mimic the Ca(2+)-mobilizing response of the LH receptor. We conclude that the LH receptor has the capability of activating two intracellular signaling pathways: one leading to stimulation of adenylyl cyclase and resulting in increases in cAMP and a second leading to stimulation of phospholipase C and resulting in formation of inositol phosphates and elevations in [Ca2+]i. These data correlate positively with and provide a mechanistic explanation for previous reports on the ability of hCG to mobilize phosphoinositides and increasing [Ca2+]i in luteal and granulosa cells (e.g. Davis, J. S., West, L. A., and Farese, R. V. (1984) J. Biol. Chem. 259, 15028-15034).
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PMID:Evidence for dual coupling of the murine luteinizing hormone receptor to adenylyl cyclase and phosphoinositide breakdown and Ca2+ mobilization. Studies with the cloned murine luteinizing hormone receptor expressed in L cells. 131 10

To assess sites and mechanism of action of prostaglandin E2 (PGE2) on water permeability (PF), we determined PGE2 effects on antidiuretic hormone (ADH)- and adenosine 3',5'-cyclic monophosphate (cAMP)-stimulated PF in rat terminal inner medullary collecting ducts perfused in vitro. PGE2 (10(-7) M) reversibly inhibited ADH-stimulated PF (1.131 +/- 192 to 532 +/- 208 microns/s). In contrast to that observed in rabbit, PGE2 also inhibited an established PF response to the exogenous cAMP analogue 8-p-(chlorophenylthio)-cAMP (696 +/- 107 to 399 +/- 99 microns/s). PGE2 alone had no effect on PF. The protein kinase C inhibitor staurosporine (10(-8) M) blocked PGE2-mediated inhibition of cAMP-stimulated PF. PGE2 caused a rapid spikelike increase in intracellular calcium [( Ca2+]i) followed by a stable elevation above basal values. Only the latter effect was abolished in a zero calcium bath. Neither staurosporine nor cAMP altered the [Ca2+]i response. These studies are the first to demonstrate PGE2-mediated inhibition of an established PF response to cAMP independent of changes in intracellular cAMP. The pattern of [Ca2+]i release and sensitivity to staurosporine suggests that this effect is mediated via signaling through phospholipase C. The results underscore the importance of species differences, axial heterogeneity, and/or in vivo conditioning for functional expression of cellular signaling pathways.
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PMID:PGE2 inhibits water permeability at a post-cAMP site in rat terminal inner medullary collecting duct. 131 24

Ribonucleoside-diphosphate reductase (ribonucleotide reductase, EC 1.17.4.1) is the enzyme responsible for the in vivo production of deoxyribonucleotides for DNA synthesis and is essential for cell proliferation. We examined the signal transduction pathways leading to expression of the M1 and M2 subunits of this enzyme in Swiss 3T3 mouse fibroblasts by Northern blot analysis. Stimulation of quiescent cells resulted in coordinate expression of both subunits, beginning at 8 hr after serum addition, in late G1 phase, and peaking at 18-24 hr. Serum increased M2 message to 30 to 50 times that of quiescent cells, in contrast with M1 message, which was increased 10 times. Agents that elevated cAMP, including forskolin, and the cAMP analogue 8-bromo-cAMP modestly stimulated gene expression. Each of these agents was synergistic with insulin, and these combinations induced expression equivalent to that induced by serum stimulation. Likewise, agents that activate protein kinase C such as phorbol 12,13-dibutyrate, bombesin, and vasopressin were also synergistic with insulin with respect to ribonucleotide reductase gene expression, as was epidermal growth factor, which stimulates receptor tyrosine kinase activity. The time course for induction of mRNA expression by each of these agents alone or in combination was identical to that for induction stimulated by serum. Finally, the synergistic effects apparent in Northern analysis of ribonucleotide reductase gene expression were mirrored in parallel determinations of DNA synthesis. Thus, the combinatorial nature of signal transduction pathways resulting in proliferation of Swiss 3T3 cells is expressed at the level of ribonucleotide reductase gene expression.
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PMID:Synergistic and coordinate expression of the genes encoding ribonucleotide reductase subunits in Swiss 3T3 cells: effect of multiple signal-transduction pathways. 131 43

Short-term desensitization to hormone-induced cAMP accumulation was investigated in the medullary (MTAL) and the cortical (CTAL) thick ascending limbs of Henle's loop isolated by microdissection from the rat kidney. The following agonists were studied: vasopressin, glucagon and human calcitonin in the MTAL, and vasopressin, glucagon, human calcitonin, parathyroid hormone (PTH) and the beta-adrenergic agonist isoproterenol in the CTAL. Isolated tubules were preincubated in vitro for 60 min in the presence or absence of a maximal concentration of one of the five agonists (vasopressin 10 nM, glucagon 10 nM, calcitonin 100 nM, PTH 10 nM, isoproterenol 1 microM). Desensitization induced by each agent to its own action was then quantified by measuring the amount of cAMP accumulating in the presence of the phosphodiesterase inhibitor isobutylmethylxanthine and the same agonist concentration as that used during preincubation. In the MTAL, as previously reported, preincubation with vasopressin led to a marked (80%-85%) desensitization to this hormone. A significant hormone self-induced desensitization of about 45% was also obtained with glucagon, but not with calcitonin. In the CTAL, the following order of potency to elicit desensitization was observed: vasopressin (80%) greater than isoproterenol (50%) greater than glucagon (30%) greater than PTH (20%, NS) greater than calcitonin (10%, NS). Thus, the magnitude of desensitization varied greatly from one hormone to another, but for a given hormone, was of roughly similar extent in both MTAL and CTAL.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Differential short-term desensitization to vasopressin, isoproterenol, glucagon, parathyroid hormone and calcitonin in the thick ascending limb of rat kidney. 131 67

Fructose-1,6-diphosphate (FDP) is a physiological product which exhibits pharmacological properties. This study shows that FDP (1-3 mM) inhibits platelet aggregation induced by the agonists thrombin, vasopressin, platelet activating factor, ADP, adrenaline, arachidonate and the stable thromboxane analogue U 44069. Thrombin-promoted ATP secretion and cytosolic Ca2+ rise are also drastically inhibited by FDP, which decreases, although to a lesser extent, the protein kinase C-dependent phosphorylation of the 47 kDa protein. The inhibition on thrombin-induced aggregation is shared, albeit less efficiently, by glucose-1,6-diphosphate and fructose-2,6-diphosphate but not by other phosphorylated monosaccharides (fructose-1:2 cyclic,6-diphosphate, glucose-1- and glucose-6-phosphate, fructose-1- and fructose-6-phosphate, mannose-6-phosphate and 5-phosphoryl ribose-1-pyrophosphate). FDP does not affect platelet activation induced by the protein kinase C activators dioctanoylglycerol or phorbol 12-myristate 13-acetate. No increase of cAMP concentration is observed in FDP-treated platelets. Altogether, these results indicate that FDP inhibits platelet activation at a level preceding phospholipase C. The data are consistent with a general inhibitory action of FDP on signal transmission.
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PMID:Fructose-1,6-diphosphate inhibits platelet activation. 131 5

The state of phosphorylation of phenylalanine hydroxylase was determined in isolated intact rat hepatocytes. 32P-labeled phenylalanine hydroxylase was immunoisolated from cells loaded with 32Pi or from cell extracts 'back-phosphorylated' with [gamma-32P]ATP by cAMP-dependent protein kinase. The rate of phenylalanine hydroxylase phosphorylation in cells with elevated cAMP was similar to that observed for the isolated enzyme phosphorylated by homogeneous cAMP-dependent protein kinase. The phosphorylation rate in cAMP-stimulated cells was increased up to four times (reaching 0.018 s-1) by the presence of phenylalanine, the phosphate content (mol/mol hydroxylase) increasing to 0.5 from the basal level (0.17) in 50 s. The half maximal effect of phenylalanine was obtained at a physiologically relevant concentration (110 microM). The synthetic phenylalanine hydroxylase cofactor dimethyltetrahydropterin also enhanced the cAMP-stimulated phosphorylation of phenylalanine hydroxylase, presumably by displacing the endogenous cofactor, tetrahydrobiopterin. Phenylalanine was a negative modulator of the phosphorylation of phenylalanine hydroxylase induced by incubating cells with vasopressin or with the phosphatase inhibitor okadaic acid. The same site on the phenylalanine hydroxylase was phosphorylated in response to these two agents as in response to elevated cAMP. The available evidence suggested that not only vasopressin, but also okadaic acid, acted by stimulating the multifunctional Ca2+/calmodulin-dependent protein kinase II or a kinase with closely resembling properties.
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PMID:Phenylalanine positively modulates the cAMP-dependent phosphorylation and negatively modulates the vasopressin-induced and okadaic-acid-induced phosphorylation of phenylalanine 4-monooxygenase in intact rat hepatocytes. 131 38

Osteonectin (SPARC, culture shock protein, BM-40) is a widely distributed glycoprotein which binds calcium and several extracellular matrix proteins, including interstitial collagens and thrombospondin, but whose physiologic role remains undefined. In the present studies, we have demonstrated that immunoreactive osteonectin is present in the distal cortical tubule and medullary tubules of murine kidney. We surveyed the renal epithelial cell lines LLC-PK1, MDCK, and OK for the expression of mRNA encoding osteonectin. We found that osteonectin mRNA is expressed by LLC-PK1 and OK cells but not by MDCK cells, as well as by adult kidney from several species. Calcitonin and vasopressin, agents which increase cAMP in these cells, were found to decrease steady-state osteonectin mRNA concentrations. We found that LLC-PK1 cells produced osteonectin protein, that the protein was localized to intracellular granules, and that the protein bound hydroxyapatite in vitro. Pulse-chase analysis revealed that osteonectin was secreted from the cell layer to the medium after a lag time of four to six hours and was secreted preferentially from the basolateral domain of the cell. The preferential secretion of the calcium-binding protein osteonectin from the renal epithelial cell is consistent with several possible functions, including a structural extracellular matrix protein, a participant in transepithelial ion transport, and an inhibitor of extracellular calcification.
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PMID:Renal tubular epithelial cells express osteonectin in vivo and in vitro. 131 80

LLC-PK1/PKE20 cells (a continuous epithelial cell line) has two different Na/H exchange activities: Na/H-1 located in the basolateral membrane and Na/H-2 located in the apical membrane [Casavola et al. (1989) Biochem Biophys Res Commun 165:833-837; Haggerty et al. (1988) Proc Natl Acad Sci USA 86:6797-6801]. In the present report we have studied hormone regulation of these exchange activities by measuring Na-dependent recovery of pHi from an acid load (by using microspectrofluorometry and 2,7-bis(carboxyethyl)-5,6-carboxyfluorescein) in response to activation of regulatory cascades by either pharmacological agents or by vasopressin or calcitonin. Agents leading to activation of protein kinase A (cAMP-dependent), such as forskolin (10 microM), 8-Br-cAMP (0.25 mM), and isobutylmethylxanthine (0.5 mM), inhibited Na/H-2 and Na/H-1 by an average of 49%. Stimulation of protein kinase C by a phorbol ester (phorbol 12-myristate 13-acetate, TPA, 100 nM) inhibited Na/H-2 (by an average of 48%) and stimulated Na/H-1 (by an average of 38%); these effects of TPA were also observed in the presence of forskolin (100 microM). Addition of either vasopressin (2 microM) or calcitonin (0.3 microM) onto both sides of the monolayer decreased the activity of Na/H-2 by an average of 26.3% and 27.7% respectively, and stimulated the activity of Na/H-1 by an average of 17.4% and 38.7% respectively; exposure of cells to either hormone stimulated production of cAMP and inositol trisphosphate, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Polarized expression of Na+/H+ exchange activity in LLC-PK1/PKE20 cells: II. Hormonal regulation. 131 51


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