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Query: UNIPROT:P01185 (
vasopressin
)
23,126
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We studied cyclic 3',5'-nucleotide phosphodiesterase (PDE) isozymes and their role in adenosine 3',5'-cyclic monophosphate (
cAMP
) and cGMP metabolism in a rat inner medullary collecting duct (IMCD) cell line. The homogenized and fractionated IMCD cells of
cAMP
-PDE and all of cGMP-PDE activity were found in the cytosol. The majority of cytosolic
cAMP
-PDE (greater than 50%) was isozyme PDE-IV; the Ca(2+)-calmodulin-sensitive PDE-I was present only in cytosol. Preincubation of IMCD cells with PDE-IV inhibitor rolipram markedly (5x) enhanced levels of
cAMP
both basal and in the presence of [Arg8]
vasopressin
(AVP). Cilostamide (for PDE-III) or vinpocetine had no effect, whereas PDE-I inhibitor 8-methoxymethyl-3-isobutyl-1-methylxanthine (8-MeoM-IBMX) enhanced AVP-dependent
cAMP
levels. Exposure of IMCD cells to 2 microM ionomycin decreased both basal and AVP-stimulated
cAMP
. Depletion of Ca2+ by preincubation of IMCD cells in the Ca(2+)-free medium with ethylene glycol-bis (beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid markedly enhanced the stimulatory response of
cAMP
to AVP, and addition of 8-MeoM-IBMX further enhanced the AVP response. The levels of cGMP, basal or in response to atriopeptin (ANP), were not affected by PDE-V inhibitor zaprinast, but both inhibitors of PDE-I, 8-MeoM-IBMX and vinpocetine, increased basal cGMP, and 8-MeoM-IBMX also increased cGMP levels enhanced by ANP. The depletion of Ca2+ from IMCD cells alone had no effect on cGMP levels, but effects of 8-MeoM-IBMX and vinpocetine on the ANP-stimulated cGMP levels were enhanced.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Cyclic 3',5'-nucleotide diesterases in dynamics of cAMP and cGMP in rat collecting duct cells. 132 Mar 33
The effect of papaverine, an inhibitor of the phosphodiesterase responsible for breakdown of
cAMP
, on the transepithelial sodium transport across the isolated frog skin was investigated. Serosal addition of papaverine caused initially an increase in the short-circuit current (SCC), a doubling of the cellular
cAMP
content and a depolarization of the intracellular potential under SCC conditions (Vscc). The initial increase in the SCC was followed by a pronounced decrease both in the SCC and in the natriferic action of
antidiuretic hormone
(
ADH
), but papaverine had no inhibitory effect on the ability of
ADH
to increase the cellular
cAMP
content. As SCC declines, no hyperpolarization was observed. The I/V relationship across the apical membrane during the inhibitory phase, revealed that papaverine reduces the sodium permeability of the apical membrane (PNaa) as well as intracellular sodium concentration. These observations and the previously noted effect of papaverine on Vscc indicates that papaverine must have an effect on the cellular Cl or K permeability. The basolateral Na,K,2Cl cotransporter was blocked with bumetanide, which should bring the cellular chloride in equilibrium. Bumetanide had no effect on basal SCC and Vscc. When papaverine was added to skins preincubated with bumetanide, the effect of papaverine on SCC and Vscc was unchanged. Therefore, the depolarization of Vscc, observed during the papaverine-induced inhibition of the SCC, must be due to a reduction in the cellular K permeability. In conclusion, it is suggested that papaverine reduces the sodium permeability of the apical membrane and the potassium permeability of the basolateral membrane of the frog skin epithelium.
...
PMID:Papaverine reduces the sodium permeability of the apical membrane and the potassium permeability of the basolateral membrane in isolated frog skin. 132 Dec 50
The role of adenosine 3',5'-cyclic monophosphate (
cAMP
)-dependent protein kinase A (PKA) in mediating the hydrosmotic effect of
vasopressin
in in vitro microperfused rabbit cortical collecting ducts (CCDs) was examined. We measured PKA substrate phosphorylation and water permeability [hydraulic conductivity (Lp) = 10(-7) cm.atm-1.s-1], stimulated by substituted
cAMP
analogues selective for a unique
cAMP
binding site (site A or B) on PKA regulatory subunit (R). Synergy between site A- and site B-selective analogues suggests involvement of PKA, because both sites must be occupied for R to dissociate from the catalytic subunit (C), allowing phosphorylation to proceed. As single agents, the site B-selective analogues 8-(4-chlorophenylthio)-
cAMP
(8-CPT) and 8-thiomethyl-
cAMP
(8-SCH3) were at least two orders of magnitude more potent than the site A-selective analogues N6-monobutyryl-
cAMP
(N6-mono) or N6-benzoyl-
cAMP
(N6-benz). Combinations of subthreshold concentrations of two site A analogues (N6-mono+N6-benz) or two site B-selective analogues (8-CPT + 8-SCH3) failed to significantly increase protein phosphorylation or water permeability. In contrast, combination of a site A plus site B analogue synergistically stimulated both protein phosphorylation and Lp. Rp-cAMPS, an inhibitor of
cAMP
binding to PKA, reduced both
vasopressin
(41% inhibition)- and
cAMP
(56% inhibition)-stimulated water permeability. H-89 (50 microM), an inhibitor of PKA kinase activity, also blocked
cAMP
-stimulated water permeability (90% inhibition). These findings suggest that
vasopressin
-induced water permeability in the rabbit CCD is mediated by PKA.
...
PMID:cAMP-dependent protein kinase mediates hydrosmotic effect of vasopressin in collecting duct. 132 38
We have investigated the regulatory actions of endothelin-1 (ET-1) on inositol phosphate accumulation, cytosolic free Ca2+ ion concentrations ([Ca2+]i), and basal and FSH-stimulated progesterone and
cAMP
accumulation by swine granulosa cells in serum-free cultures. ET-1 induced a rapid stimulation of phosphoinositide hydrolysis in populations of granulosa cells, as inferred by the rapid appearance of soluble inositol polyphosphates in response to ET-1 exposure. At the single cell level, fura-2 videomicroscopy was used to measure [Ca2+]i in individual granulosa cells. We observed cell-cell variability in the threshold concentration of ET-1 required to induce a rise in [Ca2+]i. More than 75% of granulosa cells responded to maximal doses of ET-1. The following parameters of [Ca2+]i were influenced by ET-1 concentration: percentage of responding cells, lag time for the onset of response, amplitude, and kinetics of the response. Two types of ET-1-mediated [Ca2+]i rises were observed. One type exhibited rapid Ca2+ kinetics, reaching at least a 2-fold increase above basal (spike phase) within 1-10 sec and returning to a new steady state (plateau phase) 2 min after onset. The other mode of response had slower [Ca2+]i kinetics, in which 50 sec or more were required to double [Ca2+]i, which remained at this level throughout the observation period (2.5 min). These responses to ET-1 were specific and were not initiated by
vasopressin
or tumor necrosis factor-alpha. In cell population studies using monolayer cultures of swine granulosa cells, ET-1 inhibited FSH-stimulated accumulation of progesterone and
cAMP
. The ET-1-mediated inhibition of FSH-stimulated accumulation of progesterone required at least 4 h of ET-1 exposure. The ET-1-mediated inhibition of both the FSH-stimulated accumulation of progesterone and
cAMP
after 24-h incubation was mimicked by an activator of protein kinase-C, phorbol 12-myristate 13-acetate, but not by an inactive phorbol. These observations in either single cells or populations of swine ovarian (granulosa) cells are consistent with a possible regulatory role of an ET-1-activated intracellular signaling pathway involving inositol phosphates, [Ca2+]i, and protein kinase-C in the mammalian granulosa cell.
...
PMID:Actions of endothelin-1 on swine ovarian (granulosa) cells. 132 59
1. In freshly prepared rat renal papillary tubules, endothelin-related peptides inhibited the
vasopressin
-stimulated accumulation of
cAMP
. No inhibition was observed when tubules were cultured overnight ex vivo. 2. Endothelin-1, endothelin-3 and sarafatoxin S6b had similar potencies as inhibitors of
cAMP
accumulation, indicating an endothelin (ETb) receptor. 3. These results demonstrate an interaction between ETb receptors and
vasopressin
receptors at the level of their signal transduction pathways, and show that this relationship is lost following cell culture.
...
PMID:Interaction between vasopressin and endothelin in renal papillary tubules: uncoupling following cell isolation and culture. 132 87
Protein synthesis in isolated rat hepatocytes was determined from the incorporation of [3H]leucine (4 mM) into acid-precipitable material in the presence of amino acids at twice their physiological concentration. Protein synthesis increased linearly with time and incubated cell protein, and was inhibited by cycloheximide by more than 95%. In normo-osmotic incubations containing amino acids at twice the physiological concentration the rate of [3H]leucine incorporation was 5.8 +/- 0.2 nmol/h per mg of cell protein (n = 26). Hyperosmotic cell shrinkage due to addition of 60 mM-NaCl or 120 mM-raffinose inhibited [3H]leucine incorporation into acid-precipitable material by 60 and 74% respectively, whereas hypo-osmotic cell swelling was ineffective. Inhibition of protein synthesis by adding 120 mM-raffinose was largely counteracted by simultaneous lowering of the NaCl concentration by 60 mM. Glutamine (10 mM) had no effect on protein synthesis in normo-osmotic incubations (320 mosM), but stimulated protein synthesis in hyperosmotically (440 mosM) pre-shrunken cells almost to rates found in normo-osmotic (320 mosM) control incubations.
Cyclic AMP
and
vasopressin
inhibited protein synthesis by 23% and 8% respectively, whereas insulin and phenylephrine were ineffective. However, inhibition of protein synthesis by cyclic AMP was about twice as strong in the presence of
vasopressin
or phenylephrine. When protein synthesis was preinhibited by cyclic AMP, [3H]leucine incorporation was stimulated by glutamine (10 mM), insulin or hypo-osmotic exposure. There was a close relationship between the inhibition of protein synthesis and the extent of hepatocyte shrinkage induced by the above-mentioned effectors, suggesting a role of cell volume in the regulation of hepatic protein synthesis.
...
PMID:Liver cell volume and protein synthesis. 132 28
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.
...
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.
...
PMID:The mobile receptor hypothesis revisited: a mechanistic role for hormone receptor lateral mobility in signal transduction. 133 80
Our studies on Madin-Darby canine kidney (MDCK) cells have demonstrated that high-affinity specific muscarinic receptors coupled to the phosphoinositide system are present in these cells. To determine whether muscarinic receptors in MDCK cells are linked negatively to the adenylate cyclase system, we measured the effect of muscarinic agonists and antagonists on
vasopressin
-, isoproterenol-, and forskolin-stimulated adenosine 3',5'-cyclic monophosphate (
cAMP
) formation. Vasopressin produced a maximum stimulation of
cAMP
formation of 13 pmol.10(6) cells-1.2 min-1 at 10(-7) M. Isoproterenol and forskolin stimulated
cAMP
formation production to 21 pmol.10(6) cells-1.2 min-1 and 64 pmol.10(6) cells-1.10 min-1, respectively, at 10(-4) M. The effects of
vasopressin
, isoproterenol, and forskolin were blocked by arecoline, a cholinergic agonist, in a concentration-dependent manner. The arecoline response was blocked by treatment of the cells with pertussis toxin. The inhibition by arecoline of forskolin-stimulated
cAMP
formation was reversed by various muscarinic antagonists in the following order of potency: 4-diphenyl-acetoxy-N-methylpiperidine > p-fluorohexahydrosiladifenidol > pirenzepine > methoctramine. This order of potency of muscarinic antagonists is similar to that observed in our radioligand binding studies and is consistent with the M3 subtype of muscarinic receptors. Our results indicate that muscarinic receptors in MDCK cells are coupled negatively to the adenylate cyclase system via pertussis toxin-sensitive G protein. It is concluded that this intracellular system may at least be partially responsible for the action of cholinergic agonists in these cells and in the kidney.
...
PMID:Muscarinic receptors in MDCK cells are coupled to multiple messenger systems. 133 90
In deoxycorticosterone acetate (DOCA)-NaCl hypertension, the effects of
vasopressin
(VP) in the cortical collecting tubule (CCT) are exaggerated. These include both the biochemical effect of VP-stimulated adenosine 3',5'-cyclic monophosphate (
cAMP
) formation in the CCT and physiological effects of VP-mediated sodium and water retention. In this study, we examined the mechanism of enhanced VP-stimulated
cAMP
formation in the CCT. We compared
cAMP
formation in response to activators (following in parentheses) of the VP receptor (VP), of the stimulatory guanine nucleotide binding (Gs) protein [guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S); F-], and of the catalytic subunit of adenylyl cyclase (forskolin, Mn2+) between control and DOCA-NaCl-treated rats. The effects of VP and forskolin were enhanced in CCT of DOCA-NaCl-treated animals by 201 and 139%, respectively, compared with control animals. Other activators, Mn2+ (150%), F- (142%), and GTP gamma S (156%), also caused augmented
cAMP
formation in the CCT of DOCA-NaCl-treated rats. The DOCA-NaCl-induced increment in
cAMP
response to VP remained after pretreatment of the rats with pertussis toxin (171 and 169% increase in response in DOCA-NaCl and control rats, respectively), suggesting that altered inhibitory guanine nucleotide binding (Gi) protein function is not the mechanism for the altered response to VP in the CCT. Further evidence that Gi function is intact in DOCA-NaCl animals is that epinephrine (via alpha 2-adrenoceptor stimulation) inhibited VP-stimulated
cAMP
accumulation to a similar degree in DOCA-NaCl and control rats (86 and 76%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:DOCA-enhanced sites of vasopressin-stimulated cAMP formation in rat cortical collecting tubule. 133 10
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