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)

Vasoactive intestinal peptide (VIP) and d-ala2-methionine enkephalinamide (DALA, a long-lasting enkephalin analogue) were used to investigate the peptidergic control of lacrimal gland function. To characterize the mechanism by which VIP stimulates and DALA inhibits lacrimal peroxidase secretion, the effect of these peptides on adenylate cyclase was measured. In addition, enzyme activity was measured in the presence of forskolin alone or in combination with DALA. VIP stimulated adenylate cyclase in a time- and dose-dependent manner. Negative control of adenylate cyclase was shown with the addition of DALA to membrane preparations. The enkephalin analogue inhibited basal activity approximately 65% at the maximum dose tested. The percent inhibition of VIP-stimulated activity by DALA was similar to the inhibition of basal activity. To determine if the inhibition of stimulated activity occurred at level of the VIP receptor, the effect of DALA on the response to forskolin was measured. Forskolin-stimulated adenylate cyclase activity was significantly reduced to approximately 50% in the presence of DALA. We conclude that lacrimal gland adenylate cyclase is subject to peptidergic regulation involving both stimulatory and inhibitory receptor-mediated controls.
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PMID:Peptidergic stimulation and inhibition of lacrimal gland adenylate cyclase. 217 Feb 90

Vasoactive intestinal peptide (VIP) at a concentration of 1 microM stimulates adenylate cyclase (AC) in isolated rabbit renal preglomerular arterial vessels by 3.9 +/- 1.3 fold (n = 6) over basal values. A comparable stimulation of AC was observed with prostaglandin E1. Half-maximal VIP-stimulated activity was observed at 7.2 +/- 3.5 nM (n = 6), which was increased to 17.4 +/- 4.4 nM by 10 microM-(4Cl-D-Phe6,Leu17)VIP, a VIP-receptor antagonist.
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PMID:Vasoactive intestinal peptide stimulation of adenylate cyclase activity in isolated rabbit renal arterial microvessels. 222 58

Pituitary-adenylate-cyclase-activating polypeptide (PACAP) is a novel 38-amino-acid neuropeptide isolated from ovine hypothalamic tissues based on its activity of stimulating adenylate cyclase of rat pituitary cells. Binding sites for PACAP were studied in rat tissue membranes using a 27-amino-acid N-terminal derivative of PACAP [PACAP(1-27)] labelled with 125I. Particularly high specific binding sites of 125I-PACAP(1-27) were noted in the hypothalamus, brain stem, cerebellum and lung. Specific binding sites are also present in the pituitary gland, but at a lower concentration, and mainly in the anterior lobe. Very low concentration of 125I-PACAP(1-27)-binding sites were found in the colon, aorta and kidney membranes and no binding sites were detected in the pancreas and testis. Maximal binding of 125I-PACAP(1-27) was observed at pH 7.4. Interaction of 125I-PACAP(1-27) with its binding site was rapid, specific and saturable as well as time, pH and temperature dependent. PACAP(1-27) is more potent than PACAP in displacing the binding of 125I-PACAP(1-27) with brain membranes [concentration that inhibits 50% of the binding (IC50) = 7.45 +/- 1.52 nM and 11.45 +/- 3.65 nM, respectively; mean +/- SEM, n = 4] and lung membranes (IC50 = 4.41 +/- 0.87 nM and 10.68 +/- 3.09 nM, respectively). Vasoactive intestinal peptide displaced the binding of 125I-PACAP(1-27) in lung membrane (IC50 = 16.88 +/- 5.14 nM) but not in brain membranes. The equilibrium binding of 125I-PACAP(1-27) at 4 degrees C was characterized by a single class of binding site for the brain membrane with a dissociation constant (Kd) of 2.46 +/- 0.53 nM and a maximal binding capacity (Bmax) of 8.44 +/- 3.13 pmol/mg protein, but there were two classes of binding site for lung membranes with Kd of 1.02 +/- 0.51 nM and 5.19 +/- 0.99 nM, and Bmax of 2.84 +/- 0.72 pmol/mg protein and 9.13 +/- 1.89 pmol/mg protein, respectively. These findings suggest that subtypes of PACAP-binding sites exist and PACAP may have a physiological role in the hypothalamus/pituitary axis as well as in other regions of the brain and lung.
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PMID:Binding sites of a novel neuropeptide pituitary-adenylate-cyclase-activating polypeptide in the rat brain and lung. 224 90

Vasoactive intestinal peptide (VIP) and peptide (P) with N-terminal histidine and C-terminal isoleucine (PHI) stimulated prolactin (PRL) secretion from GH4C1 cells equipotent with ED50 values of 30-50 nM. In a parafusion system optimized to give high time resolution both VIP and PHI increased PRL secretion with a delay of about 60 s and subsequent to the activation of the adenylate cyclase. Thyroliberin (TRH) increased PRL secretion within 4 s. The dose-response curves for VIP- and PHI-stimulated cAMP accumulation were superimposable on those for PRL secretion. At submaximal concentrations the effects of VIP and PHI on both cAMP accumulation and PRL secretion were additive, whereas the effects were not additive at concentrations giving maximal effects. VIP and PHI increased [Ca2+]i measured by quin-2 in a different way than TRH, without inducing changes in the electrophysiological membrane properties of the GH4C1 cells. We conclude that both VIP and PHI stimulate PRL secretion via a cAMP-dependent process involving an increase in [Ca2+]i.
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PMID:Vasoactive intestinal peptide and peptide with N-terminal histidine and C-terminal isoleucine increase prolactin secretion in cultured rat pituitary cells (GH4C1) via a cAMP-dependent mechanism which involves transient elevation of intracellular Ca2+. 243 88

Vasoactive intestinal peptide (VIP) is a putative neurotransmitter found in the salivary glands of many species, including the rat parotid gland. Parasympathetic denervation has been reported to deplete VIP in the rat parotid gland and to lead to supersensitivity to this peptide in vivo. We have compared the effects of VIP on acini isolated from parasympathetically denervated and unoperated parotid glands to examine possible supersensitivity to the peptide in vitro. VIP normally produced responses similar to those obtained with a low concentration of the beta adrenergic agonist isoproterenol (ISO), but strikingly different from the effects obtained with the muscarinic agonist carbachol (CARB). In parotid membrane preparations, VIP stimulated adenylate cyclase activity. Dissociated acini treated with VIP showed increases in cAMP accumulation and amylase release which were potentiated by forskolin and also by inhibition of phosphodiesterase. After parasympathetic denervation, maximal effects of VIP on adenylate cyclase, cAMP accumulation and amylase release in intact cells were increased two- to five-fold over contralateral control (or unoperated) parotid responses. The increase in adenylate cyclase-mediated responses after denervation was specific to VIP; there was no increased response nor increased sensitivity of any of these responses to ISO. Specific [125I]VIP binding to parotid acini increased two-fold per gland and three-fold per mg of protein after denervation; this probably explains the observed increases in the response to VIP.
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PMID:Parasympathetic denervation increases responses to VIP in isolated rat parotid acini. 247 29

Vasoactive intestinal peptide (VIP) has been shown to stimulate adenylate cyclase activity in plasma membranes isolated from canine renal cortex, outer and inner medulla in vitro. Though related hormones such as glucagon also stimulate adenylate cyclase in these membrane preparations, it is likely that VIP interacts with specific VIP receptors since the VIP receptor antagonist, (4Cl-D-Phe6, Leu17)-VIP, is capable of reducing the response to VIP, but not that to glucagon. Also binding of 125I-VIP to cortical renal plasma membranes shows competition by unlabelled VIP, but not by glucagon. Strain 1 (and clone CL(8)1b cells derived from the established cultured dog kidney cell line, MDCK, have been shown also to respond selectively to VIP by an increase in adenylate cyclase activity and cyclic AMP accumulation in intact cells. A physiological correlate of VIP activation of adenylate cyclase has been sought by addition of VIP to reconstituted epithelial monolayers of strain 1 MDCK cells clamped in Ussing chambers. VIP addition to the basal-lateral cell aspects generates an inward short-circuit current that is sensitive to replacement of medium Cl- by NO3-, and to inhibition by the Cl- channel blocker, 3-nitro-2(3-phenylpropylamino)-benzoic acid, consistent with VIP stimulation of transepithelial Cl- secretion.
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PMID:Vasoactive intestinal peptide control of renal adenylate cyclase: in vitro studies of canine renal membranes and cultured canine renal epithelial (MDCK) cells. 254 73

Vasoactive intestinal peptide (VIP) induces phosphorylation of a basic 38,000 mol. wt protein in a human lymphoblastic cell line (Molt 4b) and a human colon carcinoma cell line (HT29). In both cell types, VIP interacts with specific high affinity receptors to activate adenylate cyclase and cAMP-dependent protein kinase. The two cell types appear to express homologous receptors with similar affinity and specificity for VIP, but the colonic epithelial cells express a greater number of receptors. HT29 colonic cells also exhibit a greater stimulation of adenylate cyclase and a higher phosphorylation index for the 38,000 mol. wt protein in response to VIP. This 38,000 mol. wt protein, which is phosphorylated in the presence of VIP, appears to be identical in both cell lines; it is phosphorylated in both lymphoblasts and colonic epithelial cells in the presence of forskolin, but not in the presence of phorbol 12-myristate 13-acetate. Phosphorylation of this 38,000 mol. wt protein may be an important step in VIP regulation of water and electrolyte secretion from colonic epithelial cells, and in VIP regulation of immunoglobulin and lymphokine secretion from lymphocytes.
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PMID:Comparison of vasoactive intestinal peptide-mediated protein phosphorylation in human lymphoblasts and colonic epithelial cells. 277 Jul 50

Vasoactive intestinal peptide (VIP) is found in the enteric nervous system of all layers of the small intestine. In the gastrointestinal tract, VIP receptors coupled to adenylate cyclase are present on epithelial, smooth muscle and possibly mononuclear cells. This study analyzes the distribution of VIP binding using in vitro autoradiographic techniques. VIP binding was present in high density in the mucosal layer of rabbit duodenum, jejunum and ileum. Low VIP binding was noted over the smooth muscle layers or the lymphoid follicles. Similar results were obtained in rat small intestine. The density of VIP binding was greatest in duodenal mucosa but was present in lower density in jejunal and ileal mucosa. Again, low VIP binding was noted in the smooth muscle layers or lymphoid follicles. Thus, autoradiographic maps of small intestine indicate that VIP receptors are found primarily in the small intestinal mucosa.
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PMID:Autoradiographic distribution of vasoactive intestinal polypeptide receptors in rabbit and rat small intestine. 283 2

Vasoactive intestinal peptide (VIP) is a neuropeptide with a broad range of biological activities in various tissues. After interaction with its membrane receptor, VIP generally induces a very large increase in the intracellular cyclic AMP level. Receptors for VIP have been described in numerous tissues and cell lines. The first results on VIP receptor structure have been obtained by covalent cross-linking using bifunctional reagents. The molecular mass of the different components characterized in this way differs greatly according to the species and the tissue used. This heterogeneity may reflect either a difference in the length of the cross-linked polypeptide backbone or differently glycosylated forms of the same polypeptide. The VIP binding site of intact human adenocarcinoma cells (HT29 cells) is an Mr 64,000 glycoprotein with 20kDa of N-linked oligosaccharide side chains containing sialic acid. The structure of the VIP binding site from HT29 cell is compared, first to the structure of the VIP receptor from other tissues, particularly that from rat liver, and second to the structure of the hepatic glucagon binding site. Recently, solubilization of the VIP receptor in an active form has provided a new way of studying this receptor. The HT29 cell line is an appropriate model to study the dynamics of the VIP receptor. After binding to its receptor, VIP is rapidly internalized, probably by receptor-mediated endocytosis. This internalization leads to a decrease in the cell surface receptor number and simultaneously to a homologous desensitization of adenylate cyclase. VIP is then degraded in the lysosomes, while most of the receptors are recycled back to the cell surface. The presence of an intracellular pool of unoccupied VIP receptors has been demonstrated after inactivation of the cell surface receptors by chymotrypsin. The kinetics of the receptor reappearance at the cell surface, after inactivation by chymotrypsin or after receptor-mediated endocytosis, indicate 2 possible intracellular pathways for occupied and unoccupied VIP receptors.
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PMID:The vasoactive intestinal peptide (VIP) receptor: recent data and hypothesis. 285 63

Vasoactive intestinal peptide (VIP) had two types of effects on the longitudinal muscle of the mouse distal colon. At low concentrations (10(-8) M) VIP induced a contraction which seemed to be related to the production of prostaglandins as it was abolished after preincubation with indomethacin (10(-6) M). At higher concentrations (3 X 10(-8) and 10(-7) M) VIP induced relaxations which developed slowly and were related to stimulation of the adenylate cyclase activity of the smooth muscle cells. There is no evidence that VIP is the non-adrenergic, non-cholinergic transmitter released by electrical stimulation in this preparation and responsible for rapid relaxation of the smooth muscle.
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PMID:Evidence against VIP as the inhibitory transmitter in non-adrenergic, non-cholinergic nerves supplying the longitudinal muscle of the mouse colon. 287 96


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