Elevation of Intracellular Cyclic AMP and Stimulation of Adenylate Cyclase Activity by Vasoactive Intestinal Peptide and Glucaeon in the Retinal Pigment Epithelium

1984 ◽  
Vol 43 (6) ◽  
pp. 1522-1526 ◽  
Author(s):  
Shav-Whey M. Koh ◽  
Gerald J. Chader
Keyword(s):  
Retinal Pigment Epithelium ◽  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Vasoactive Intestinal Peptide ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Stimulation Of

Effect of histamine on canine gastric mucosal adenylate cyclase.

1977 ◽  
Vol 232 (1) ◽  
pp. E35
Author(s):  
R R Dozois ◽  
A Wollin ◽  
R D Rettmann ◽  
T P Dousa
Keyword(s):  
Gastric Mucosa ◽  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Antral Mucosa ◽  
Fundic Mucosa ◽  
H2 Receptors ◽  
Dose Dependent ◽  
Stimulation Of

The effects of histamine, Nalpha-dimethylhistamine, 4,5-methylhistamine, Ntau-methylhistamine, pentagastrin, carbachol, and NaF on the adenylate cyclase activity from canine gastric mucosa were investigated in cell-free preparations. In gastric fundic mucosa, histamine (10(-4) M), Nalpha-dimethylhistamine (10(-4) M), 4,5-methylhistamine (10(-4 M), and NaF (10)-2) M) significantly (P less than 0.001) increased adenylate cyclase activity (means+/-SE) by 44.7+/-6.6, 49.4+/-6.7, 34.0+/-6.4, and 572.0+/-100%, respectively, above basal activity. The effect of histamine and Na-dimethyl histamine was dose-dependent. In contrast, other tested agents failed to stimulate the formation of cyclic AMP in gastric fundic mucosa. Metiamide (10(-4) M) blocked the stimulation of fundic mucosa adenylate cyclase by histamine and Nalpha-dimethylhistamine, without significantly altering basal and NaF-induced adenylate cyclase activity. Histamine, however, did not stimulate the adenylate cyclase activity from the gastric antral mucosa. The findings support the proposal that the canine gastric acid response to histamine may be mediated by cyclic AMP formed in response to stimulation of histamine H2-receptors.

scholarly journals Regulation of adenylate cyclase and cyclic AMP phosphodiesterase by 5-hydroxytryptamine and calcium ions in blowfly salivary-gland homogenates

1982 ◽  
Vol 204 (1) ◽  
pp. 153-159 ◽  
Author(s):  
I Litosch ◽  
M Fradin ◽  
M Kasaian ◽  
H S Lee ◽  
J N Fain
Keyword(s):  
Salivary Gland ◽  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Guanine Nucleotides ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Cyclic Amp Phosphodiesterase ◽  
Maximal Stimulation ◽  
Increased Activity ◽  
Stimulation Of

Salivary-gland homogenates contain 5-hydroxytryptamine-stimulated adenylate cyclase. Half-maximal stimulation was obtained with 0.1 microM-5-hydroxytryptamine in the presence of added guanine nucleotides. Gramine antagonized the stimulation of cyclase caused by 5-hydroxytryptamine. In the presence of hormone, guanosine 5′-[gamma-thio]triphosphate produced a marked activation of adenylate cyclase activity. Stimulation of adenylate cyclase by forskolin or fluoride did not require the addition of guanine nucleotides or hormone. In the presence of EGTA, Ca2+ produced a biphasic activation of cyclase activity. Ca2+ at 1-100 microM increased activity, whereas 2000 microM-Ca2+ inhibited cyclase activity. The neuroleptic drugs trifluoperazine and chlorpromazine non-specifically inhibited adenylate cyclase activity even in the absence of Ca2+. The cyclic AMP phosphodiesterase activity in homogenates was not affected by Ca2+ or exogenous calmodulin. This enzyme was also inhibited by trifluoperazine in the absence of Ca2+. These results indicate that Ca2+ elevates adenylate cyclase activity, but had no effect on cyclic AMP phosphodiesterase of salivary-gland homogenates.

Antisecretory effects of berberine in rat ileum

1981 ◽  
Vol 241 (3) ◽  
pp. G253-G258 ◽  
Author(s):  
Y. H. Tai ◽  
J. F. Feser ◽  
W. G. Marnane ◽  
J. F. Desjeux
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Rat Ileum ◽  
Ion Secretion ◽  
Stimulation Of

The in vitro antisecretory effects of the alkaloid berberine (1.0 mM) on intestinal ion secretion and mucosal adenylate cyclase and Na-K-ATPase activities were studied in the rat ileum. Mucosal berberine did not alter the individual basal net ion fluxes and basal adenylate cyclase activity but decreased short-circuit current (Isc) and increased the net absorption of chloride plus bicarbonate. In the cholera toxin-treated tissue, mucosal berberine stimulated absorption of Na and Cl and inhibited the increased adenylate cyclase activity but did not change the specific Na-K-ATPase activity, whereas serosal berberine stimulated Na secretion and decreased Isc. Mucosal berberine also decreased Isc, increased Cl permeability, and reversed the ion secretion induced by dibutyryl cyclic AMP, the heat-stable enterotoxin of Escherichia coli, and methylprednisolone administration. The antisecretory effects of mucosal berberine may be explained by stimulation of a Na-Cl-coupled absorptive transport process. The mechanism of action of serosal berberine remains to be elucidated. However, it is clear that mucosal berberine affects intestinal ion transport by mechanisms different from stimulation of the Na pump and probably at a step distal to the production or degradation of cyclic AMP or cyclic GMP.

scholarly journals The rapid desensitization of glucagon-stimulated adenylate cyclase is a cyclic AMP-independent process that can be mimicked by hormones which stimulate inositol phospholipid metabolism

1987 ◽  
Vol 243 (1) ◽  
pp. 39-46 ◽  
Author(s):  
G J Murphy ◽  
V J Hruby ◽  
D Trivedi ◽  
M J O Wakelam ◽  
M D Houslay
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Membrane Fraction ◽  
Phospholipid Metabolism ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Kinase C ◽  
Independent Process ◽  
Inositol Phospholipid ◽  
Stimulation Of

Treatment of intact hepatocytes with glucagon, TH-glucagon [(1-N-alpha-trinitrophenylhistidine, 12-homoarginine]glucagon), angiotensin or vasopressin led to a rapid time- and dose-dependent loss of the glucagon-stimulated response of the adenylate cyclase activity seen in membrane fractions isolated from these cells. Intracellular cyclic AMP concentrations were only elevated with glucagon. All ligands were capable of causing both desensitization/loss of glucagon-stimulated adenylate cyclase activity and stimulation of inositol phospholipid metabolism in the intact hepatocytes. Maximally effective doses of angiotensin precluded any further inhibition/desensitizing action when either glucagon or TH-glucagon was subsequently added to these intact cells, as has been shown previously for the phorbol ester TPA (12-O-tetradecanoylphorbol 13-acetate) [Heyworth, Wilson, Gawler & Houslay (1985) FEBS Lett. 187, 196-200]. Treatment of intact hepatocytes with these various ligands caused a selective loss of the glucagon-stimulated adenylate cyclase activity in a washed membrane fraction and did not alter the basal, GTP-, NaF- and forskolin-stimulated responses. Angiotensin failed to inhibit glucagon-stimulated adenylate cyclase activity when added directly to a washed membrane fraction from control cells. Glucagon GR2 receptor-stimulated adenylate cyclase is suggested to undergo desensitization/uncoupling through a cyclic AMP-independent process, which involves the stimulation of inositol phospholipid metabolism by glucagon acting through GR1 receptors. This action can be mimicked by other hormones which act on the liver to stimulate inositol phospholipid metabolism. As the phorbol ester TPA also mimics this process, it is proposed that protein kinase C activation plays a pivotal role in the molecular mechanism of desensitization of glucagon-stimulated adenylate cyclase. The site of the lesion in desensitization is shown to be at the level of coupling between the glucagon receptor and the stimulatory guanine nucleotide regulatory protein Gs, and it is suggested that one or both of these components may provide a target for phosphorylation by protein kinase C.

scholarly journals Regulation of GH3 pituitary tumour-cell adenylate cyclase activity by activators of protein kinase C

1989 ◽  
Vol 262 (3) ◽  
pp. 829-834 ◽  
Author(s):  
L A Quilliam ◽  
P R M Dobson ◽  
B L Brown
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Maximal Response ◽  
Kinase C ◽  
Cyclic Amp Accumulation ◽  
Stimulation Of

The influence of protein kinase C (PKC) activation on cyclic AMP production in GH3 cells has been studied. The stimulation of cyclic AMP accumulation induced by forskolin and cholera toxin was potentiated by 4 beta-phorbol 12,13-dibutyrate (PDBu). Moreover, PDBu, which causes attenuation of the maximal response to vasoactive intestinal polypeptide (VIP), also induced a small right shift in the dose-response curve for VIP-induced cyclic AMP accumulation. PDBu-stimulated cyclic AMP accumulation was unaffected by pretreatment of cells with pertussis toxin or the inhibitory muscarinic agonist, oxotremorine. PDBu stimulation of adenylate cyclase activity required the presence of a cytosolic factor which appeared to translocate to the plasma membrane in response to the phorbol ester. The diacylglycerol-generating agents thyroliberin, bombesin and bacterial phospholipase C each stimulated cyclic AMP accumulation, but, unlike PDBu, did not attenuate the stimulation induced by VIP. These results suggest that PKC affects at least two components of the adenylate cyclase complex. Stimulation of cyclic AMP accumulation is probably due to modification of the catalytic subunit, whereas attenuation of VIP-stimulated cyclic AMP accumulation appears to be due to the phosphorylation of a different site, which may be the VIP receptor.

Cytochemical Evidence for Presynatic β-Adrenergic Regulation of Secretion in the Developing Rat Submandibular Gland

1977 ◽  
Vol 35 ◽  
pp. 430-431
Author(s):  
L.S. Cutler
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Submandibular Gland ◽  
Neonatal Rat ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Parotid Glands ◽  
Adrenergic Agonist ◽  
Rat Submandibular Gland

Many studies previously have shown that the B-adrenergic agonist isoproterenol and the a-adrenergic agonist norepinephrine will stimulate secretion by the adult rat submandibular (SMG) and parotid glands. Recent data from several laboratories indicates that adrenergic agonists bind to specific receptors on the secretory cell surface and stimulate membrane associated adenylate cyclase activity which generates cyclic AMP. The production of cyclic AMP apparently initiates a cascade of events which culminates in exocytosis. During recent studies in our laboratory it was observed that the adenylate cyclase activity in plasma membrane fractions derived from the prenatal and early neonatal rat submandibular gland was retractile to stimulation by isoproterenol but was stimulated by norepinephrine. In addition, in vitro secretion studies indicated that these prenatal and neonatal glands would not secrete peroxidase in response to isoproterenol but would secrete in response to norepinephrine. In contrast to these in vitro observations, it has been shown that the injection of isoproterenol into the living newborn rat results in secretion of peroxidase by the SMG (1).

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