Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:4.6.1.1 (adenylate cyclase)
19,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Incubation of rat extraorbital lacrimal gland slices with the beta-agonist isoproterenol caused peroxidase secretion but no K+ release. The peroxidase secretion was inhibited by propranolol. Addition of dibutyryl cyclic AMP or adenosine 3'5'-cyclic phosphorothioate to lacrimal slices produced peroxidase secretion at a higher rate than that obtained with optimal concentration of isoproterenol. Methyl isobutylxanthine is also a strong stimulator of peroxidase secretion. Peroxidase activity was determined by a modified sensitive guaiacol method. Membrane fraction of lacrimal cells was shown to contain an isoproterenol-stimulated adenylate cyclase activity. It is therefore suggested that there is a beta-adrenergic receptor in the rat lacrimal gland and that its stimulation causes activation of an adenylate cyclase which leads to peroxidase secretion.
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PMID:beta-Adrenergic receptors stimulated peroxidase secretion from rat lacrimal gland. 616 88

The arachidonate inhibition of the adenylate-cyclase system of cultured pig thyroid cells was not mediated by cyclooxygenase, lipoxygenase or peroxidase metabolites. Indeed ETYA, an inhibitor of cyclooxygenase and lipoxygenase, and methimazole, an inhibitor of peroxidase and iodination were without effect on the arachidonate inhibition. Moreover the effect of arachidonate was amplified by a combination with ETYA. In 32P incorporation experiments we observed a modification of the labelling of individual phospholipids of cultured pig thyroid cells resulting in a decrease into phosphatidylinositol (PI) and an increase into phosphatidate (PA) of arachidonate and ETYA-treated cells. These results may be explained by an inhibition of CDP-diacylglycerol: inositol transferase and conversely a stimulation of PI specific phospholipase C yielding a decrease in PI and an increase in PA, which inhibits in turn adenylate cyclase activity possibly by Ca2+ translocation.
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PMID:Effects of eicosatetraynoic acid (ETYA) on cultured pig thyroid cells. Relationships between the inhibition of the phosphatidate-phosphatidyl inositol cycle, the iodination and the cyclic AMP responsiveness to thyrotropin. 618 61

Regulation of cellular content of the endogenous opioid peptides Met5-enkephalin and Leu5-enkephalin was investigated in neuroblastoma X glioma hybrid cells NG108-15 grown in both serum-supplemented and serum-free defined media. Untreated cells and cells induced to differentiate were stained using anti-Met5-enkephalin and anti-Leu5-enkephalin with the peroxidase-antiperoxidase immunocytochemical technique at the light microscopic level. In untreated NG108-15 cells grown in serum-supplemented medium, intense enkephalin-like immunoreactivity was localized in cell bodies and short processes of a select population of cells. The volume fraction of stained untreated cells remained constant throughout the time period investigated. When cells were induced to differentiate with N6,O2'-dibutyryl adenosine 3':5'-cyclic monophosphate (dBcAMP) or 8-bromo cyclic adenosine monophosphate (1.0 mM) treatment for 5 days, staining was found throughout the cytoplasm of perikarya and the extensive processes which were expressed, and the volume fraction of stained cells increased over 2-fold. Receptor-mediated stimulation of adenylate cyclase by prostaglandin E1 (10 microM) for 5 days produced results similar to those with dBcAMP. Pure cultures of differentiated cells with intense staining were obtained by further treatment of cultures, grown in the presence or absence of dBcAMP, with arabinosylcytosine (araC). Untreated, dBcAMP-treated and araC-treated NG108-15 cells grown in defined medium expressed staining patterns and volume fractions of stained cells similar to those grown in serum-supplemented medium; sodium butyrate (1.0 mM), however, increased the volume fraction of stained cells grown in defined medium over 3-fold, whereas it had little effect on staining of cells grown with serum. The presence of both Met5- and Leu5-enkephalin-like activities in NG108-15 cells was confirmed in acid extracts of cells by radioreceptor assay after separation by reverse phase high pressure liquid chromatography. Induction of differentiation in NG108-15 cells by dBcAMP treatment increased the cellular concentration of both enkephalins to over 2 times the levels found in untreated cells. The biochemical analysis for Met5-enkephalin- and Leu5-enkephalin-like activity compared well with the immunocytochemical data indicating that the enkephalin content is correlated with the state of differentiation of NG108-15 cells.
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PMID:Induction of differentiation increases Met5-enkephalin and Leu5-enkephalin content in NG108-15 hybrid cells: an immunocytochemical and biochemical analysis. 619 53

To characterize the role of cyclic nucleotides in secretion of enzymes by the lacrimal gland, pieces of rat exorbital glands were perfused with (1) 8-bromoadenosine-3',5'-cyclic monophosphate (8 Br cyclic AMP), (2) 8-bromoguanosine-3',5'-cyclic monophosphate (8 Br cyclic GMP), (3) forskolin, a stimulator of adenylate cyclase activity, (4) 3-isobutyl-1-methylxanthine (IBMX), an inhibitor of phosphodiesterase activity, or (5) carbachol, a cholinergic agonist. As a measure of enzyme secretion, timed collections of the perifusate effluent were analysed for peroxidase, an enzyme secreted by the lacrimal gland. Control peroxidase secretion was 0.3-0.9 (u./min per milligram protein). Peroxidase secretion was stimulated by 8 Br cyclic AMP (1 mM), but not by 8 Br cyclic GMP (1 mM). A 2-fold increase was detected. Peroxidase secretion was also stimulated by forskolin (60 microM), IBMX (1 mM), and the cholinergic agonist carbachol, which all stimulated peroxidase secretion 2-or 3-fold. The effect of maximally effective concentrations of IBMX (1 mM) and carbachol (0.1 mM) on secretion was additive. Finally, Ca2+ depletion in the presence of EGTA (1 mM) inhibited both IBMX-and carbachol-induced secretion by 45% and 60% respectively. We conclude that cyclic AMP, but not cyclic GMP, can stimulate lacrimal gland enzyme secretion. Cyclic AMP appears to utilize a pathway separate from but convergent with cholinergic agonists.
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PMID:Cyclic nucleotide-dependent enzyme secretion in the rat lacrimal gland. 620 48

A variety of proteins and tissue preparations (rabbit erythrocyte lysate, catalase, peroxidase, creatine phosphokinase, and lima bean trypsin inhibitor) contain protein activator(s) of the extracellular adenylate cyclase of intact Bordetella pertussis organisms. Stimulation of adenylate cyclase activity of up to 1000-fold over basal activity can be obtained. Activation of the adenylate cyclase is due to the presence of calmodulin in these protein preparations. The criteria to establish this were: Ca2+ dependence of the activation, inhibition by trifluoperazine, heat stability of the activator, chromatographic behavior like authentic calmodulin, and stimulation of cyclic nucleotide phosphodiesterase by the activators. The great sensitivity of the B.pertussis adenylate cyclase assay makes this and ideal system for the detection of trace amounts of calmodulin, in the presence of large amounts of other proteins.
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PMID:Spurious protein activators of Bordetella pertussis adenylate cyclase. 626 34

In the present study, the expression of beta-adrenergic receptors, the activity of the enzyme adenylate cyclase (AC), and the intracellular concentration of cyclic adenosine 3',5'-monophosphate (cAMP) were investigated in HL-60 cells before and after their differentiation to monocytic or more mature granulocytic cells. Treatment of the HL-60 promyelocytes with 12-O-tetradecanoylphorbol 13-acetate or human interleukin 2 resulted in the appearance of cells with monocytic characteristics (morphology, non-specific esterase, adherence, reaction with a monocyte-specific monoclonal antibody). Induction with retinoic acid resulted in differentiation to cells with typical features of mature granulocytes (morphology, peroxidase, nitro-blue tetrazolium reduction). During maturation to monocytes, the density of beta-adrenergic receptors decreased, whereas it remained constant during maturation to granulocytes. In comparison with normal circulating monocytes or polymorphonuclear granulocytes, expression of beta-adrenergic receptors on the surface of the differentiated HL-60 cells was low. Activation of AC by the hormones isoproterenol, prostaglandin E1, and histamine generally decreased with HL-60 maturation and enzyme activities were markedly below those measured in normal peripheral leukocytes. In the induced monocytic HL-60 cells, the weak effectiveness of isoproterenol was due to the loss of beta-adrenergic receptors. In the induced granulocytic HL-60 cells, the reduced hormonal AC activation could be explained by the impaired coupling between hormone receptors and catalytic enzyme unit. The concentration of intracellular cAMP after differentiation of HL-60 cells reflected the increase in basal AC activity and the decrease in hormone stimulation of the enzyme. Our data indicate that HL-60 cells induced to differentiate possess some monocyte- and granulocyte-like properties, but do not meet several important functional criteria of their new cell identities.
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PMID:[In vitro differentiation of leukaemic promyelocytes (HL-60): effect on beta-adrenergic receptors and adenylate cyclase activity]. 631 Aug 99

The binding and internalization of cholera toxin (CT) into the intestinal epithelium were studied in vivo in rats. The distribution of CT was ascertained using immunofluorescence and by immunoenzyme-electron microscopy, with horse-radish peroxidase anti-CT antibodies as the conjugate. The toxin was rapidly bound and internalized into both epithelial and goblet cells; CT was evenly distributed on the microvilli at the bases of which it appeared in invaginations (coated pits). Though not found in nuclei, CT appeared intracellularly in coated vesicles, and dissolved in the cytoplasm where it was enriched at the terminal web. The basolateral membrane, except for the tight junctions, was outlined with CT; some staining also appeared in the basement membrane, in fibroblasts, macrophages and in the blood-vessel walls in the submucosa. The lysosomatotrophic agent chloroquine simultaneously inhibited CT-induced fluid secretion and intracellular distribution of CT in the cytoplasmic matrix, but not in the vesicles. The inhibitor of CT-action on adenylate cyclase, chlorpromazine, did not affect the cellular distribution of CT. Our results suggest that CT mainly is internalized by endocytosis into the intestinal epithelium. The toxin is probably released from vesicles into the cytoplasm via secondary lysosomes.
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PMID:Internalization in vivo of cholera toxin in the small intestinal epithelium of the rat. 636 57

Adrenergic-sensitive adenylate cyclase was found to be present in the nucleus accumbens and ventral caudate of the rabbit, but displayed less activity in the dorsal caudate. In general, stimulation of the enzyme by dopamine (DA) was most sensitive to inhibition by fluphenazine while norepinephrine (NE)-stimulated activity was highly sensitive to both fluphenazine and propranolol. Other selective adrenergic-receptor blocking agents (butoxamine, practolol, yohimbine and prazosine) were more effective in antagonizing the effect of NE as opposed to DA-activation. Activation of adenylate cyclase by NE in the dorsal caudate displayed less sensitivity to these adrenergic antagonists than in the other two areas. Horseradish peroxidase-positive cells were present in the locus coeruleus, following injection into the nucleus accumbens. Activity of basal and guanosine triphosphate (GTP)-sensitive adenylate cyclase was reduced by enkephalins in these three brain regions. This action was reversed by naloxone. Met-enkephalin did not affect either NE- or DA-mediated responses in any area.
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PMID:Monoamine activation and enkephalin inhibition of adenylate cyclase in dorsal and ventral striatum of the rabbit. 647 80

Two novel peptides, named PACAP (pituitary adenylate cyclase activating polypeptide) containing 38 (PACAP38) and 27 residues (PACAP27) were recently isolated from ovine hypothalami. In order to investigate the pituitary cell type(s) that bear a receptor for PACAP, PACAP38 was biotinylated and used for cytochemical examination of binding. The cells were also identified by immunocytochemical methods using the antisera against each of the rat anterior pituitary hormones or an antiserum against S-100 protein, a marker for pituitary folliculo-stellate (FS) cells. Biotinylated PACAP38 (biot-PACAP) exhibited adenylate cyclase stimulating activity (ACSA) comparable to PACAP38 in rat pituitary cell cultures, and displaced the bound 125I-PACAP27 to the rat pituitary membrane preparation to the same extent as PACAP38. After 2-4 days of culture, dispersed rat pituitary cells were incubated with varying concentrations of biot-PACAP at room temperature or 4 degrees C. The bound biot-PACAP38 was visualized by avidin-biotin-peroxidase complex (ABC) method with nickel intensification. Biot-PACAP-positive and pituitary hormone or S-100-positive cells were counted. More than 90% of S-100-positive cells bound biot-PACAP38. A considerable number of GH and PRL cells and a lesser number of ACTH cells also bound biot-PACAP38, whereas only a few identified LH, FSH, or TSH cells bound biot-PACAP38. These results suggest that FS cells are a major target cell type for PACAP. A recent study from our laboratory demonstrated that PACAP stimulated the release of interleukin (IL)-6 in rat pituitary cell cultures. FS cells are known to produce IL-6.
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PMID:Cytochemical characterization of anterior pituitary target cells for the neuropeptide, pituitary adenylate cyclase activating polypeptide (PACAP), using biotinylated ligands. 844 7

The transepithelial route for mucosa-to-serosa transport of the tracer macromolecule horseradish peroxidase (HRP; MW 40 kDa) and modulation of this transport by forskolin and carbachol have been studied in vi-tro in stripped goldfish intestinal epithelium mounted in Ussing-type chambers. Uptake and transport have been investigated by measuring the HRP flux from the muco-sal to serosal sides by an enzymatic method and by visualising HRP reaction products in the mucosa with electron-microscopical techniques. Both the cholinergic agonist carbachol (which is thought to increase intracellular Ca2+ and activate protein kinase C activity) and forskolin (a direct activator of adenylylcyclase) affect the amount of enzymatically active HRP in the tissue. In control tissue, HRP product is found only within the epithelial cells, the transepithelial flux reaching a constant value of about 1.5 pmoles/cm2 per h. Carbachol increases the amount of HRP product in the cells, but has no significant effect on the HRP flux compared with control values. Forskolin decreases the amount of HRP product in the cells; however, in the presence of forskolin, the lateral intercellular spaces become filled with HRP product. HRP is found in the lamina propria and the transepithelial protein flux increases more than 2.5-fold. In the presence of forskolin plus carbachol, the results are no different from the control. It is concluded that carbachol increases the endocytotic uptake of HRP, whereas forskolin inhibits the uptake but increases the paracellular permeability for HRP in goldfish intestine.
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PMID:Influence of forskolin and carbachol on intestinal absorption of horseradish peroxidase in the goldfish (Carassius auratus). 876 57


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