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

Lysine vasopressin did not increase plasma FFAs level in man and in rat Pitressin and lysine vasopressin did not influence adenyl cyclase activity in rat epididymal fat pad, while ornithine vasopressin induced a statistically significant adenyl cyclase increment. These findings suggest that the adipokinetic acticity of ADH which has been correlated only with the amino acid arginine is also correlated with ornithine.
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PMID:Antidiuretic hormone and lipolysis. 114 94

Two series of neurohypophysial peptide amino-acylated derivatives were tested for their ability to activate plasma membrane adenylate cyclase prepared from pig or rat kidney. They were firstly [8-lysine]-vasopressin-related derivatives (Na-[Glycyl-Cys]1-[8-Lysine]-vasopressin and Na-[Glycyl-Glycyl-Cys51-[8-Lysine]-vasopressin) and secondly oxytocin-related derivatives (Na-[Glycyl-Cys-a1)-oxytocin, Na-[Leucyl-Glycyl-Glycyl--Cys]-oxytocin, and Na-[Glycyl-Cys]-[2-0methyl tyrosine]-oxtocin). The maximal adenylate cyclase activation induced by these peptides was lower than that induced by their respective parent hormones. After incubation of these analogues with plasma membranes obtained from the renal medulla, no significant release of parent hormones occurred. Good qualitative correlations were observed between relative antidiuretic activities measured in vivo and relative potencies in activating adenylate cyclase. It was concluded that direct action of peptides tested on the kidney is at least partly responsible for their antidiuretic activity in vivo.
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PMID:Renal adenylate cyclase activation by amino acylated vasopressin and oxytocin. 114 16

Vasopressin analogues with enhanced antidiuretic activity in vivo (deamino-[D-arg8]-vasopressin, deamino-6-carba-[Orn8]-vasopressin, deamino-6-carba-[Arg8]-vasopressin, and deamino-6-carba-[D-Arg8]-vasopressin) were tested for their ability to activate rat renal medullary adenylate cyclase and compared to the natural antidiuretic hormones [Arg8]- and [Lys8]-vasopressin. The enzyme preparation used did not inactivate the vasopressins or the analogues tested. The analogues activated adenylate cyclase. However, several of them were far less effective than expected on the basis of their very high in vivo antidiuretic activity. It was concluded that the enhanced in vivo activity reflects greater metabolic stability in vivo rather than enhanced affinity for the renal antidiuretic hormone receptor.
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PMID:Activation of rat kidney adenylate cyclase by vasopressin analogues: lack of correlation with antidiuretic activity. 114 17

The effect of bovine growth hormone on adenylate cyclase activity was studied in bovine and rat renal medulla. Highly purified growth hormone (lot B1003A) increased adenylate cyclase activity in plasma membranes from bovine renal medulla from 132+/-6 pmol cyclic AMP formed/mg protein per 10 min to 364+/-10 pmol cyclic AMP formed/mg protein per 10 min. Similar results were seen with homogenates of rat renal medulla. The minimum effective concentration of bovine growth hormone required to activate adenylate cyclase was 0.5 mug/ml and maximum activation was detected at 500 mug/ml. The amount of vasopressin determined by radioimmunoassay to contaminate the growth hormone caused an increase in adenylate cyclase activity comparable to that of the corresponding concentration of growth hormone that was tested. Dialysis of growth hormone and vasopressin resulted in parallel reductions in the effect of each hormone on adenylate cyclase activity. Similarly, both growth hormone and vasopressin produced increases in short circuit current in isolated toad bladders but these effects were not detectable after dialysis of the hormones. In contrast, the effect of growth hormone on the uptake of 35SO2-4 by cartilage from hypophysectomized rats was not decreased after dialysis. These results indicate that available preparations of growth hormone are contaminated by small but physiologically significant amounts of vasopressin and that the activation of adenylate cyclase activity in renal medulla in response to growth hormone can be explained by this contamination rather than by an effect of growth hormone per se.
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PMID:Activation of adenylate cyclase in renal medulla by bovine growth hormone. An artifact attributable to vasopressin. 117 31

The sensitivity to catecholamines of the adenylate cyclase (AC) activity contained in single tubule samples was investigated on 10 different well defined segments, isolated by microdissection from collagenase treated rabbit kidneys. No responsiveness to isoproterenol (10(-6) M) was observed in the proximal tubule (convoluted and straight portions), the thin descending and thick ascending limbs of the loop of Henle, and the first ("bright") portion of the distal convoluted tubule (DCTb); in contrast high responses (stimulation factors: 4 to 6 fold) were obtained in the second ("granular") portion of the distal convoluted tubule (DCTg), as well as in both the "granular" (CCTg) and the "light" (CCTl) portions of the cortical collecting tubule. In absolute value, however, the CCTl response was definitely lower than those measured in DCTg and CCTg, as is its control activity. In the medullary portion of the collecting tubule, the AC response to isoproterenol was rather poor both in absolute and relative terms. Dose-response curves measured on DCTg samples indicated a threshold response with an isoproterenol concentration below 10(-8) M; half maximal effect corresponded to about 3 x 10(-8) M. CCTl sensitivity to isoproterenol was of the same order of magnitude. Isoproterenol as well as norepinephrine effects in DCTg and CCTl were completely suppressed by 10(-4) M propranolol, indicating that the observed AC stimulation was mediated via receptors of the beta type. In beta blocked CCTl, 10(-6) M norepinephrine did not inhibit vasopressin-induced AC stimulation; in the presence of 10(-6) M norepinephrine, 10(-4) M phentolamine resulted in no additional AC stimulation in DCTg and CCTl; these data suggest the absence of alpha receptors inhibiting AC activity in these structures. In DCTg, AC stimulation induced either by 10(-6) M isoproterenol or by 1 U/ml PTH were observed to be additive when the two hormones were given together. The presence of catecholamine-dependent AC activity in three distal portions of the rabbit nephron is discussed in relation to its possible physiological implications.
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PMID:Catecholamine sensitive adenylate cyclase activity in different segments of the rabbit nephron. 123 46

In experiments on frog urinary bladder the mechanisms behind the gradual development of a hydroosmotic reaction to antidiuretic hormone (ADH) were investigated. It was suggested that the velocity of hydroosmotic reaction may be limited by (a) formation and insertion of particle aggregates into the apical membrane or (b) by velocity of cAMP formation. The urinary bladders were exposed to 23 nM ADH for different times (from 1 to 20 min) and water flow was measured over a period of 40 min. It was found that the value of the full hydroosmotic response increased progressively with the time of exposure to the hormone; however, the enhancement of water flow was equal during each time interval before reaching the reaction maximum. A direct correlation between the value of ADH-stimulated water flow, cAMP content in bladder tissue and frequency of particle aggregates in the granular cell apical membrane was observed. The content of cAMP in ADH-treated bladders was higher by 80% in the absence than in the presence of an osmotic gradient. Pretreatment of urinary bladders with 50 microM cyclic nucleotide phosphodiesterase inhibitor, 3-isobutyl-1-methylxanthine, significantly accelerated the development of the hydroosmotic reaction and increased the magnitude of water flow in comparison with the effect of ADH only. No changes in cyclic AMP phosphodiesterase activity were found in the urinary bladder homogenates under the action of ADH, so it seems likely that accumulation of cAMP depends only on the increase of adenylate cyclase activity.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Does the gradual hydroosmotic response to antidiuretic hormone depend on intracellular cAMP accumulation or on the formation of intramembrane particle aggregates? 127 17

To assess whether receptor binding is sufficient to initiate vasopressin receptor endocytosis in cells expressing the vasopressin V1 or V2 receptors, we synthesized a novel fluorescent-labeled vasopressin analog, [1-(beta-mercapto-beta, beta-cyclopentamethylene propionic acid), 2-(O-ethyl)-D-tyrosine, 4-valine, 8-lysine-N6-carboxytetramethylrhodamine] vasopressin (R-CLVP), that binds to vasopressin receptors but does not activate intracellular events such as the mobilization of intracellular calcium or the activation of adenylate cyclase. We compared the manner in which this analog was endocytosed in cells expressing V1 (A-10, rat smooth muscle cells) or V2 (LLC-PK1, porcine kidney cells) receptors with that of a full agonist, [1-(beta-mercaptopropionic acid), 8-lysine-N6-carboxytetramethylrhodamine] vasopressin (R-MLVP) [Lutz et al. (1990) J. Biol. Chem. 265, 4657-4663; Lutz et al. (1990) Proc. Natl. Acad. Sci. U.S.A. 87,6507-6511]. We showed that R-CLVP bound to both types of receptors with good affinity. It failed to increase cyclic AMP concentrations in LLC-PK1 cells and did not increase the mobilization of intracellular calcium in A-10 cells. It bound to the surface of both these cell types in a diffuse manner and it did not undergo receptor endocytosis in either cell type. In contrast, R-MLVP, an agonist that bound to both receptor subtypes and elicited changes in intracellular cyclic AMP and calcium, bound to the surface of these cells in a diffuse manner at early times after exposure, and rapidly underwent endocytosis. We conclude that binding of vasopressin to its receptors alone is insufficient to cause receptor endocytosis, and other events distal to the receptor are required to initiate endocytosis. R-CLVP should be a useful analog in determining the factors responsible for initiating receptor endocytosis.
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PMID:A vasopressin analog that binds but does not activate V1 or V2 vasopressin receptors is not internalized into cells that express V1 or V2 receptors. 130 61

Hepatocyte growth factor (HGF) is the most potent known mitogen for hepatocytes in primary culture. However, the mechanisms through which HGF induces hepatocyte proliferation have not been defined. Here we have investigated the role of the adenylate cyclase, phosphoinositidase C and tyrosine kinase signalling systems in the control of hepatocyte proliferation by HGF using freshly isolated or cultured adult rat hepatocytes. We show that human recombinant HGF caused a dose-dependent increase in hepatocyte DNA synthesis with a maximal effect at 10 ng/mL and an EC50 of 5.9 ng/mL. HGF had no effect on hepatocyte adenylate cyclase activity or intracellular cAMP levels. Elevation of hepatocyte cAMP levels resulted in inhibition of HGF-stimulated DNA synthesis. HGF stimulated inositol phospholipid hydrolysis with a maximal effect at 25 ng/mL and potentiated the effect of vasopressin (10(-8) and 10(-9)M). HGF (100 ng/mL) caused an increase in the phosphorylation on tyrosine of an unknown hepatocyte protein with a molecular mass of 36 kDa. Thus, we have shown that HGF, like epidermal growth factor (EGF), can activate the phosphoinositidase C and tyrosine kinase systems in rat hepatocytes. As with EGF, these intracellular signalling systems may underlie HGF-induced hepatocyte proliferation.
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PMID:Role of the adenylate cyclase, phosphoinositidase C and receptor tyrosyl kinase systems in the control of hepatocyte proliferation by hepatocyte growth factor. 132 55

Recent application of the technique of fluorescence photobleaching recovery to direct measurement of the lateral mobility of plasma membrane-localized hormone receptors has shed new light on the role of receptor lateral mobility in signal transduction. Receptors for insulin and EGF have been known for some time to be largely immobile at physiological temperatures. This presumably relates to their signal transduction mechanism, which appears to require intermolecular autophosphorylation (receptor aggregation) for activation. In contrast, G-protein coupled receptors must interact with other membrane components to bring about signal transduction, and it is interesting in this regard that the adenylate cyclase (AC) activating vasopressin V2-receptor is highly laterally mobile at 37 degrees C. It has recently been possible to reversibly modulate the V2-receptor mobile fraction (f) to largely varying extents, and to demonstrate thereby a direct effect on the maximal rate of in vivo cAMP production at 37 degrees C in response to vasopressin. A direct correlation between f and maximal cAMP production indicates that f may be a key parameter in hormone signal transduction in vivo, especially at sub-KD (physiological) hormone concentrations, with mobile receptors being required to effect G-protein activation.
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PMID:The mobile receptor hypothesis revisited: a mechanistic role for hormone receptor lateral mobility in signal transduction. 133 80

The distribution of binding sites for atrial natriuretic peptide (ANP) has been examined in frozen sections of the guinea pig inner ear by means of autoradiography. The highest density was found in the stria vascularis of all cochlear turns. In membrane preparations of stria vascularis in vitro, the production of the second messenger cGMP was strongly stimulated by synthetic ANP in a dose dependent manner. Adenylate cyclase was neither stimulated nor inhibited by ANP, thus suggesting, that the binding sites coincide with an ANP receptor, which is coupled to guanylate cyclase but not negatively coupled to an adenylate cyclase molecule. The production of cyclic GMP could not be reduced by GDP-beta S, a strong inhibitor of the Gs protein. We conclude the existence of an ANP receptor-guanylate cyclase signal transfer system, similar to the beta 2 receptor-adenylate cyclase system in the inner ear, without coupling to a G protein. ANP might play a role in sodium and water regulation of the endolymph and might antagonize the action of vasopressin.
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PMID:Binding sites of atrial natriuretic peptide (ANP) in the mammalian cochlea and stimulation of cyclic GMP synthesis. 133 79


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