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Khodorova A, Montmayeur JP, Strichartz G. Endothelin receptors and pain. THE JOURNAL OF PAIN 2009; 10:4-28. [PMID: 19111868 DOI: 10.1016/j.jpain.2008.09.009] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2008] [Revised: 09/08/2008] [Accepted: 09/30/2008] [Indexed: 12/11/2022]
Abstract
UNLABELLED The endogenous endothelin (ET) peptides participate in a remarkable variety of pain-relatedprocesses. Pain that is elevated by inflammation, by skin incision, by cancer, during a Sickle Cell Disease crisis and by treatments that mimic neuropathic and inflammatory pain and are all reduced by local administration of antagonists of endothelin receptors. Many effects of endogenously released endothelin are simulated by acute, local subcutaneous administration of endothelin, which at very high concentrations causes pain and at lower concentrations sensitizes the nocifensive reactions to mechanical, thermal and chemical stimuli. PERSPECTIVE In this paper we review the biochemistry, second messenger pathways and hetero-receptor coupling that are activated by ET receptors, the cellular physiological responses to ET receptor activation, and the contribution to pain of such mechanisms occurring in the periphery and the CNS. Our goal is to frame the subject of endothelin and pain for a broad readership, and to present the generally accepted as well as the disputed concepts, including important unanswered questions.
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Affiliation(s)
- Alla Khodorova
- Department of Anesthesiology, Perioperative and Pain Medicine, Pain Research Center, Brigham & Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115-6110, USA
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2
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Rodríguez MR, Sabbatini ME, Santella G, Vescina C, Vatta MS, Bianciotti LG. Vagally mediated cholestatic and choleretic effects of centrally applied Endothelin-1 through ETA receptors. ACTA ACUST UNITED AC 2006; 135:54-62. [PMID: 16712977 DOI: 10.1016/j.regpep.2006.04.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2005] [Revised: 04/03/2006] [Accepted: 04/03/2006] [Indexed: 11/17/2022]
Abstract
The role of Endothelin-1 (ET-1) in the central nervous system is not fully understood yet although several studies strongly support its neuromodulatory role. A high density of endothelin receptors is present in the dorsal vagal complex that is the major site for the regulation of the digestive function. Therefore in the present study we sought to establish the role of ET-1 in the central regulation of bile secretion in the rat. Intracerebroventricular ET-1 injection exhibited opposite behaviors on spontaneous bile secretion according to the dose administered. Lower doses of ET-1 (1 fM) increased bile flow and bicarbonate excretion whereas higher doses (1 nM) decreased bile flow and bile acid output. Both the choleretic and the cholestatic effects of ET-1 were abolished in animals pretreated with icv BQ-610 (selective ETA antagonist) but not with BQ-788 (selective ETB antagonist). In addition, truncal vagotomy but not adrenergic blockade abolished ET-1 effects on bile secretion. Brain nitric oxide was not involved in ET-1 response since L-NAME pretreatment failed to affect ET-1 actions on the liver. Portal venous pressure was increased by centrally administered ET-1 being the magnitude of the increase similar with low and high doses of the peptide. These results show that centrally applied ET-1 modified different bile flow fractions independent of hemodynamic changes. Lower doses of ET-1 increased bile acid independent flow whereas higher doses decreased bile acid dependent flow. Vagal pathways through the activation of apparently distinct ETA receptors mediated the cholestatic as well as the choleretic effects induced by ET-1. Present findings show that ET-1 participates in the central regulation of bile secretion in the rat and give further insights into the complexity of brain-liver interaction.
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Affiliation(s)
- Myrian R Rodríguez
- Cátedras de Fisiopatología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, Piso 5 (1113AAD) Buenos Aires, Argentina
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3
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Puppala BL, Bhalla S, Matwyshyn G, Gulati A. Role of endothelin (ETA) receptors in neonatal morphine withdrawal. Peptides 2006; 27:1514-9. [PMID: 16293342 DOI: 10.1016/j.peptides.2005.10.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2005] [Revised: 10/14/2005] [Accepted: 10/14/2005] [Indexed: 11/21/2022]
Abstract
We have previously demonstrated role of central endothelin (ET) receptors in neonatal morphine tolerance. The present study was conducted to investigate involvement of central ET receptors in neonatal rat morphine withdrawal. The aim was to determine activation of G-proteins coupled to opioid and ET receptors by morphine and ET ligands in neonatal rat brains during morphine withdrawal. Pregnant female rats were rendered tolerant to morphine by chronic exposure to morphine pellets over 7 days. Withdrawal was induced on day 8 by removal of pellets. Rat pups were delivered by cesarean section 24 h after pellet removal. G-protein stimulation induced by morphine; ET-1; ETA receptor antagonist, BMS182874; and ETB receptor agonist, IRL1620, was determined in the brain of neonatal rats undergoing morphine withdrawal by [35S]GTPgammaS binding assay. Morphine-induced maximal stimulation of G-protein in morphine withdrawal group (83.60%) was significantly higher compared to placebo control group (66.81%). EC50 value for ET-1-induced G-protein stimulation during morphine withdrawal (170.60 nM) was higher than control (62.5 nM). BMS182874, did not stimulate GTP binding in control but significantly increased maximal stimulation of G-proteins in morphine withdrawal (86.07%, EC50 = 31.25 nM). IRL1620-induced stimulation of G-proteins was similar in control and morphine withdrawal. The present findings indicate involvement of central ETA receptors in neonatal morphine withdrawal.
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Affiliation(s)
- Bhagya L Puppala
- Department of Pediatrics and Neonatology, Advocate Lutheran General Children's Hospital, Park Ridge, IL 60068, USA
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4
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D'Orléans-Juste P, Labonté J, Bkaily G, Choufani S, Plante M, Honoré JC. Function of the endothelinB receptor in cardiovascular physiology and pathophysiology. Pharmacol Ther 2002; 95:221-38. [PMID: 12243796 DOI: 10.1016/s0163-7258(02)00235-8] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
One of the two receptors by which the potent vasoactive effects of endothelin (ET)-1 are mediated is the ET(B) receptor (ET(BR)), which is found in several tissues, but, more importantly from a cardiovascular point of view, on the endothelial cell. The endothelial cell also has the unique capability of releasing ET-1, as well as other factors, such as the endothelial-derived relaxing factors and prostacyclin, which counteract the myotropic effects of the peptide. The secretory and contractile responses to ET-1 rely on G-protein-coupled ET(BR)s, as well as ET(A)-G-protein-coupled receptor-like proteins. The mitogenic properties of ET-1 via ET(A) receptors (ET(AR)s) coupled to mitogen-activated protein kinases and tyrosine kinases on the vascular smooth muscle may occur in conjunction with the anti-apoptotic characteristics of the endothelial ET(BR)s. Interestingly, most of the relevant antagonists and agonists for both ET(AR)s and ET(BR)s have been developed by the pharmaceutical industry. This highlights the therapeutical potential of compounds that act on ET receptors. In normal as well as in physiopathological conditions, the ET(BR) plays an important role in the control of vascular tone, and must be taken into account when using ET receptor antagonists for the treatment of cardiovascular diseases. For the management of congestive heart failure, renal failure and primary pulmonary hypertension, the most recent literature supports the use of selective ET(AR) antagonists rather than mixed antagonists of ET(AR)s and ET(BR)s. Nonetheless, validation of this view will have to await the first clinical trials comparing the actions of ET(A) to mixed ET(A)/ET(B) receptor antagonists.
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Affiliation(s)
- P D'Orléans-Juste
- Department of Pharmacology, Institut de Pharmacologie de Sherbrooke, Medical School, Université de Sherbrooke, 3001 12th Avenue North, Sherbrooke, J1H 5N4, Québec, Canada.
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5
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Shraga-Levine Z, Sokolovsky M. Functional coupling of G proteins to endothelin receptors is ligand and receptor subtype specific. Cell Mol Neurobiol 2000; 20:305-17. [PMID: 10789830 DOI: 10.1023/a:1007010125316] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
1. The aims of the present study were (a) to determine the identity of the G proteins with which the endothelin receptor interacts and whether this interaction is subtype specific and (b) to determine whether agonist exposure can result in specific coupling between the endothelin receptor and G proteins. 2. Coupling between endothelin A (ET(A)) or endothelin B (ET(B)) receptors and G proteins was assessed in two fibroblast cell lines, each expressing one receptor subtype. Four ligands, ET-1, ET-3, SRTXb, and SRTXc, were used for receptor stimulation. The G protein alpha-subunit coupled to the receptor was identified by immunoprecipitation with an antibody against the endothelin receptor and immunoblotting with specific antibodies against different G protein alpha-subunits. 3. Unstimulated ET(A) and ET(B) receptors (ET(A)R and ET(B)R, respectively) were barely coupled to Go(alpha). The unstimulated ET(A)R coimmunoprecipitated with Gi3alpha, whereas the unstimulated ETBR was much less strongly coupled to Gi3alpha. The coupling of ETBR to Gi1Gi2 alpha-subunits was much stronger than the coupling of ET(A)R to these alpha-subunits. Stimulation with the different ET agonists also resulted in differential coupling of G proteins to the receptor subtypes. All four ligands caused a strong increase in coupling of the ET(B)R to Gi3alpha, whereas coupling of the ET(A)R to this subunit was not affected by ET-1 and was even decreased by SRTXc. On the other hand, all four ligands caused a much greater increase in the coupling of ET(A)R to G(q)alpha/G11alpha than in the coupling of ET(B)R to these alpha-subunits. Ligand-induced coupling between the receptors and the Gi1 and Gi2 alpha-subunits is similar for the two receptor subtypes. The same was true for ligand-induced coupling of the receptors to Go(alpha), except that ET-3 increased the coupling of this alpha-subunit to ET(B)R and decreased the coupling to ET(A)R. Taken together, the results of this study show that coupling between ET receptors and G proteins is ligand and receptor subtype specific. 4. It remains to be established whether this diversity of receptor-G protein coupling is of relevance for the various endothelin signaling pathways and/or pathological states.
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MESH Headings
- Animals
- Blotting, Western
- Cells, Cultured
- Cricetinae
- Cricetulus
- Endothelin-1/pharmacology
- Endothelin-3/pharmacology
- Fibroblasts/cytology
- GTP-Binding Protein alpha Subunit, Gi2
- GTP-Binding Protein alpha Subunits, Gi-Go
- GTP-Binding Protein alpha Subunits, Gq-G11
- GTP-Binding Proteins/analysis
- GTP-Binding Proteins/metabolism
- Heterotrimeric GTP-Binding Proteins/analysis
- Heterotrimeric GTP-Binding Proteins/metabolism
- Ligands
- Lung/cytology
- Peptides/pharmacology
- Precipitin Tests
- Proto-Oncogene Proteins/analysis
- Proto-Oncogene Proteins/metabolism
- Receptor, Endothelin A
- Receptor, Endothelin B
- Receptors, Endothelin/agonists
- Receptors, Endothelin/analysis
- Receptors, Endothelin/metabolism
- Vasoconstrictor Agents/pharmacology
- Viper Venoms/pharmacology
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Affiliation(s)
- Z Shraga-Levine
- Department of Neurobiochemistry, Tel Aviv University, Israel
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6
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Mullaney I, Vaughan DM, MacLean MR. Regional modulation of cyclic nucleotides by endothelin-1 in rat pulmonary arteries: direct activation of G(i)2-protein in the main pulmonary artery. Br J Pharmacol 2000; 129:1042-8. [PMID: 10696107 PMCID: PMC1571930 DOI: 10.1038/sj.bjp.0703153] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/1999] [Revised: 12/09/1999] [Accepted: 12/10/1999] [Indexed: 11/09/2022] Open
Abstract
The ability of endothelin-1 (ET-1) to modulate the cyclic nucleotides, guanosine 3' 5' cyclic monophosphate (cyclic GMP) and adenosine 3' 5' cyclic monophosphate (cyclic AMP) was assessed in the main elastic pulmonary elastic artery (4 - 5 mm i.d.) and the small muscular pulmonary arteries (150 - 200 micrometer i.d.) of the rat. ET-1 caused an increase in cyclic GMP in the larger vessels but had no effect in the smaller arteries. The increase in cyclic GMP was not dependent on an intact endothelium and was inhibited by the ET(A)-receptor antagonist FR139137 (1 microM). ET-1 caused a decrease in cyclic AMP in the main pulmonary arteries, an effect that was partially blocked by FR139317 but not influenced by the ET(B)-receptor antagonist BQ-788 (1 microM) or removal of the vascular endothelium. In contrast, ET-1 caused an increase in cyclic AMP in the small vessels, an effect that was blocked by BQ-788 but unaffected by FR139317. In the main pulmonary arteries, ET-1 caused enhanced incorporation of radiolabelled ADP-ribose by cholera toxin into G(i)2 in the main pulmonary artery, an indicator of its receptor-mediated activation. In summary, we have shown that in the small muscular pulmonary artery of the rat, (where ET(B) mediated vasoconstriction prevails), there is an ET(B)-mediated increase in cyclic AMP with no net effect on cyclic GMP levels. In the large arteries, (where vasoconstriction is mediated via the ET(A) receptor), there is an ET(A)-mediated increase in cyclic GMP (endothelium independent) and an ET(A)-mediated (endothelium independent) decrease in cyclic AMP.
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Affiliation(s)
- I Mullaney
- Division of Neuroscience and Biomedical Systems, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow, G12 8QQ
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7
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Monti LD, Valsecchi G, Costa S, Sandoli EP, Phan CV, Pontiroli AE, Pozza G, Piatti PM. Effects of endothelin-1 and nitric oxide on glucokinase activity in isolated rat hepatocytes. Metabolism 2000; 49:73-80. [PMID: 10647067 DOI: 10.1016/s0026-0495(00)90763-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To test the hypothesis that endothelin-1 (ET-1) and nitric oxide (NO) influence glucokinase (GK) activity in an opposite manner, we evaluated the effects of ET-1, L-NAME, an inhibitor of NO synthase, and L-arginine, a substrate for NO synthase, on GK activity and glycogen content in isolated rat hepatocytes. Moreover, to understand the receptor involved in the process, the effects of BQ 788, a specific antagonist of ETB receptor, and PD 142893, an antagonist of ETA-ETB receptors, were also evaluated. GK activity, cyclic guanosine monophosphate (cGMP), and glycogen intracellular content were measured on isolated hepatocytes, while glucose levels and NO as NO2-/NO3- were determined in the medium. High ET-1 levels induced a 20% decrease of NO2-/NO3- levels and cGMP intracellular content, followed by a 49% reduction of GK activity and a 15% decrease of glycogen. In parallel, a 10% increase of glucose in the medium was observed. In the presence of L-NAME, GK activity and glycogen levels showed analogous decrements as observed with ET-1. Also in this case, a significant decrease of the intracellular content of cGMP was observed. No synergistic effects of ET-1 and L-NAME were observed. L-Arginine was able to counteract the inhibitory effect of ET-1 on cGMP and GK activity. Glycogen content was slightly but not significantly reduced, and under those conditions, a significant decrease of glucose in the medium was observed. When hepatocytes were incubated with ET-1 plus BQ 788 or ET-1 plus PD 142893, GK activity was unchanged. Interestingly, no changes were observed in NO2-/NO3- levels and the intracellular content of cGMP was not modified when the antagonists of ET-1 receptors were added to the medium. In conclusion, the present study shows that the NO pathway seems to be an important regulator of GK activity and glycogen content through cGMP activity. In addition, ET-1 seems to be not active per se, but its activity seems mediated by a simultaneous decrease of NO levels.
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Affiliation(s)
- L D Monti
- Istituto Scientifico H. San Raffaele, Cattedra di Clinica Medica, Medicina I, Università di Milano, Italy
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8
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Desmarets J, Frelin C. High affinity interaction of endothelin-3 with recombinant ETA receptors. Biochem Biophys Res Commun 1999; 256:357-60. [PMID: 10079188 DOI: 10.1006/bbrc.1999.0331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pharmacological evidence has suggested that endothelin-3 (ET-3) may act via a novel form of ET receptor that is shared by ETA receptor antagonists but not by ETB receptor selective agonists. This study analyses the properties of interaction of ET-3 with recombinant bovine ETA receptor. Apparent Kd(ET-3) values as low as 50 nM were defined from [125I]ET-1 binding experiments performed at low (5 microg/ml) protein concentrations in the assays. Larger (up to 1 microM) values were artefactually obtained in experiments performed at larger protein concentrations. The three monoiodo ET-3 derivatives were synthetized. ([125I]Y14)ET-3 did not recognize ETA receptors. ([125I]Y6)ET-3 labelled 18% of [125I]ET-1 binding sites with a Kd value of 320 pM. ([125I]Y13)ET-3 labelled 44% of [125I]ET-1 binding sites with a Kd value of 130 pM. High affinity ([125I]Y6)ET-3 and ([125I]Y13)ET-3 bindings were prevented by ET-1 (Kd = 5-7 pM), ET-3 (Kd = 70-250 pM), BQ-123 (Kd = 2 nM) and FR139317 (Kd = 2 nM) but not by low concentrations of 4-AlaET-1, sarafotoxin S6c or IRL1620. The three monoiodo ET-3 derivatives bound to recombinant rat ETB receptors with a pM affinity. The results suggest that ET-3, ([125I]Y6)ET-3 and ([125I]Y13)ET-3 should not be considered as ETB receptor specific ligands.
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Affiliation(s)
- J Desmarets
- Institut de Pharmacologie Moléculaire et Cellulaire, CNRS UPR 411, 660 route des Lucioles, Valbonne, 06560, France
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9
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Ding KH, Latimer AJ, Abdel-Latif AA. Activation of particulate guanylyl cyclase by endothelins in cultured SV-40 transformed cat iris sphincter smooth muscle cells. Life Sci 1999; 64:161-74. [PMID: 10027747 DOI: 10.1016/s0024-3205(98)00548-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We investigated the effects of endothelins (ETs) on cGMP production in cultured SV-40 transformed cat iris sphincter smooth muscle (SV-CISM-2) cells. ET-3 increased cGMP formation in a concentration-dependent manner (EC50 = 98nM), which was 2.5 times higher than that of ET-1. The ET(B)receptor agonists sarafotoxin-S6c and IRL 1620 also increased cGMP production, mimicking the effects of the ETs. The ET(B) receptor antagonist BQ 788, but not the ET(A) receptor antagonist BQ610, dose-dependently blocked ET-3-stimulated cGMP formation (IC50=10nM). The phorbol ester, Phorbol 12, 13-dibutyrate (PDBu), which inhibits particulate guanylyl cyclase in smooth muscle, dose-dependently inhibited ET-3-stimulated cGMP accumulation (IC50=66nM). LY83583 and ODQ, inhibitors of soluble guanylyl cyclases, as well as inhibitors of the nitric oxide cascade and of intracellular Ca2+ elevation had no appreciable effect on ET-3-induced cGMP production. ET-3 markedly inhibited carbachol-induced intracellular Ca2+ mobilization. We conclude that ET-3 increases intracellular cGMP levels in SV-CISM-2 cells through activation of the ET(B) receptor subtype and subsequent stimulation of the membrane-bound guanylyl cyclase. Elevation of cGMP by ET and the subsequent inhibition of muscarinic stimulation of intracellular Ca2+ mobilization by the cyclic nucleotide could serve to modulate the contractile effects of Ca2+-mobilizing agonists in the iris sphincter smooth muscle.
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Affiliation(s)
- K H Ding
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta 30912-2100, USA
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10
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Saadoun S, García A. Endothelin stimulates nitric oxide-dependent cyclic GMP formation in rat cerebellar astroglia. Neuroreport 1999; 10:33-6. [PMID: 10094128 DOI: 10.1097/00001756-199901180-00006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Endothelins (ETs) elicit a diversity of cellular responses in cultured astrocytes that suggest an important role of these peptides in glial cell function. Stimulation of astroglial ET receptors induces phosphoinositide (PI) hydrolysis and intracellular calcium mobilization, but little is known about the signalling events that occur downstream of this system. Here we show that in rat cerebellar astroglia in culture ETs produce a receptor-mediated stimulation of cyclic GMP (cGMP) formation that is rapid and totally dependent on nitric oxide synthase (NOS) activity. The effect is blocked by an inhibitor of PI phospholipase C, compound U73122, and by depletion of intracellular calcium stores with thapsygargin. These results indicate that calcium released by inositol trisphosphate is responsible for NOS activation and subsequent cGMP formation.
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Affiliation(s)
- S Saadoun
- Instituto de Biología Fundamental V. Villar Palasí and Departamento de Bioquímica y Biología Molecular, Universidad Autónoma de Barcelona, Bellaterra, Spain
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Hernández F, Catalán RE, Martinez AM. Endothelin enhances adenosine and isoprenaline elevated cyclic AMP levels in rat cerebellar slices. Peptides 1999; 20:1115-22. [PMID: 10499430 DOI: 10.1016/s0196-9781(99)00108-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In this study, we present evidence showing that endothelin (ET) potentiates the responses to adenosine, to 5'-N-ethylcarboxamidoad, a nonhydrolyzable adenosine agonist, and to isoprenaline. These responses seem to occur through ET-B receptors, as all three endothelin isopeptides have the same potency, sarafotoxin 6c has the same effect as ET-1, BQ-123, an ET-A receptor antagonist has no effect, and BQ-788, an ET-B receptor antagonist that totally suppresses the responses analyzed.
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Affiliation(s)
- F Hernández
- Departamento de Biologia Molecular, Centro de Biologia Molecular Severo Ochoa (CSIC-UAM), Universidad Autonoma de Madrid, Spain
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12
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Elferink JG, De Koster BM. The involvement of protein kinase G in stimulation of neutrophil migration by endothelins. Eur J Pharmacol 1998; 350:285-91. [PMID: 9696419 DOI: 10.1016/s0014-2999(98)00265-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Activation of human neutrophil migration by endothelin-1 and endothelin-3 is inhibited by guanylate cyclase inhibitors, by antagonists of protein kinase G (G-kinase), and by KT-5823, an inhibitor of G-kinase. Although no direct effect of endothelins on cGMP level could be established, these results suggest that the effect of these endothelins on migration is mediated by cGMP, and that the effect of cGMP proceeds via a G-kinase. There was little or no effect of guanylate cyclase inhibitors and G-kinase antagonists on endothelin-2-activated migration, indicating that the role of cGMP and G-kinase in endothelin-2-induced activation was either absent or at least different from that of the other endothelins. As compared with other activators, the role of G-kinase in formyl-methionyl-leucyl-phenylalanyl(fMLP-)activated migration resembled that of endothelin-activated migration, while the role of G-kinase in interleukin-8- or leukotriene B4-activated migration was less pronounced.
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Affiliation(s)
- J G Elferink
- Department of Molecular Cell Biology, University of Leiden, The Netherlands
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13
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Shraga-Levine Z, Sokolovsky M. Functional role for glycosylated subtypes of rat endothelin receptors. Biochem Biophys Res Commun 1998; 246:495-500. [PMID: 9610390 DOI: 10.1006/bbrc.1998.8646] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Glycosylation of endothelin (ET) receptors was found to occur in rat cerebellar and atrial membranes. Specifically, we investigated whether the ETA and ETB receptor subtypes differed in their sensitivity to deglycosylation treatment and whether the two affinity states (nanomolar and picomolar) observed in each receptor subtype reflect differences in glycosylation states. Pretreatment of cerebellar or atrial membranes with endoglycosidase H (endo H) caused a marked decrease in the number of maximal binding sites that bind ligand with nanomolar affinity, whereas ligand affinity remained the same. The picomolar-affinity binding sites were not affected by endo H. The use of specific antagonists indicated that the receptor subtype most likely to be influenced by glycosylation is ETA. We suggest that in both cerebellar and atrial membranes, the carbohydrate chains of the ETA receptor contribute to the binding of ligand to the nanomolar-affinity binding sites, but not to the picomolar-affinity binding sites.
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Affiliation(s)
- Z Shraga-Levine
- Department of Neurobiochemistry, Faculty of Life Sciences, Tel Aviv University, Israel
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14
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Kuwaki T, Kurihara H, Cao WH, Kurihara Y, Unekawa M, Yazaki Y, Kumada M. Physiological role of brain endothelin in the central autonomic control: from neuron to knockout mouse. Prog Neurobiol 1997; 51:545-79. [PMID: 9153073 DOI: 10.1016/s0301-0082(96)00063-9] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Although endothelin (ET) was discovered as a potent vascular endothelium-derived constricting peptide, its presumed physiological and pathophysiological roles are now considered much more diverse than originally though. Endothelin in the brain is thought to be deeply involved in the central autonomic control and consequent cardiorespiratory homeostasis, possibly as a neuromodulator or a hormone that functions locally in an autocrine/paracrine manner or widely through delivery by the cerebrospinal fluid (CSF). This notion is based on the following lines of evidence. (1) Mature ET, its precursors, converting enzymes, and receptors all are detected at strategic sites in the central nervous system (CNS), especially those controlling the autonomic functions. (2) The ET is present in the CSF at concentrations higher than in the plasma. (3) There is a topographical correspondence of ET and its receptors in the CNS. (4) The ET is released by primary cultures of hypothalamic neurons. (5) When ET binds to its receptors, intracellular calcium channels. (6) An intracerebroventricular or topical application of ET to CNS sites elicits a pattern of cardiorespiratory changes accompanied by responses of vasomotor and respiratory neurons. (7) Recently generated knockout mice with disrupted genes encoding ET-1 exhibited, along with malformations in a subset of the tissues of neural crest cell lineage, cardiorespiratory abnormalities including elevation of arterial pressure, sympathetic overactivity, and impairment of the respiratory reflex. Definitive evidence is expected from thorough analyses of knockout mice by applying conventional experimental methods.
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Affiliation(s)
- T Kuwaki
- Department of Physiology, Faculty of Medicine, University of Tokyo, Japan.
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Cardozo AM, D'Orléans-Juste P, Yano M, Frank PA, Rae GA. Influence of endothelin ET(A) and ET(B) receptor antagonists on endothelin-induced contractions of the guinea pig isolated gall bladder. REGULATORY PEPTIDES 1997; 69:15-23. [PMID: 9163578 DOI: 10.1016/s0167-0115(96)02123-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The receptors mediating guinea pig gall bladder (GPGB) contractions induced by endothelin-1 (ET-1) and related peptides were characterized using various ET receptor antagonists. As all ET-receptor agonists used, except sarafotoxin S6c (SRTX), failed to induce a clear-cut maximal response at the highest concentration tested (i.e. 100 nM), their potencies are expressed in terms of a CK50 (i.e. the concentration causing 50% of the response to 80 mM KCl). ET-1 (CK50 0.8 nM) was equipotent to ET-2 and SRTX (selective ET(B) receptor agonist), but more potent than ET-3 (5-fold) or IRL 1620 (selective ET(B) receptor agonist). BQ-123 (0.3 microM, peptidic ET(A) receptor antagonist) did not alter responses to ET-1, ET-3 or SRTX. BQ-788 (1 microM, peptidic ET(B) receptor antagonist) reduced the potency of ET-3 (9-fold at the CK50 level) and SRTX ( > 20-fold), but not ET-1. SRTX responses were unaffected by RES-701-1 (3 microM, peptidic ET(B) receptor antagonist). The combination BQ-123 (0.3 microM) plus BQ-788 (1 microM) did not modify responses to ET-1, inhibited SRTX responses similarly to BQ-788 alone and abolished ET-3 responses. Bosentan (1 microM, non-peptidic ET(A)/ET(B) receptor antagonist) reduced the potency of ET-1 (15-fold). ET-3 (9-fold) and SRTX (4-fold). In rat aorta, the antagonists blocked ET-1-induced contractions (BQ-123 and bosentan) or SRTX-induced endothelium-dependent relaxations (BQ-788, RES-701-1 and bosentan). Thus, the GPGB expresses both ET(A) and ET(B) receptors. As BQ-123 only blocked responses to ET-3 in the presence of BQ-788, there appears to be cross-talk between both receptor types. Also, the binding sites of ET-1 and ET-3 on the ET(A) receptor may not coincide entirely, as BQ-123, even in presence of BQ-788, did not affect ET-1-induced contractions.
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Affiliation(s)
- A M Cardozo
- Department of Pharmacology, CCB, Universidade Federal de Santa Catarina, Rua Ferreira Lima, Florianopolis, SC, Brazil
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Abstract
The heme oxygenase (HO) system consists of two forms identified to date: the oxidative stress-inducible protein HO-1 (HSP32) and the constitutive isozyme HO-2. These proteins, which are different gene products, have little in common in primary structure, regulation, or tissue distribution. Both, however, catalyze oxidation of heme to biologically active molecules: iron, a gene regulator; biliverdin, an antioxidant; and carbon monoxide, a heme ligand. Finding the impressive heme-degrading activity of brain led to the suggestion that "HO in brain has functions aside from heme degradation" and to subsequent exploration of carbon monoxide as a promising and potentially significant messenger molecule. There is much parallelism between the biological actions and functions of the CO- and NO-generating systems; and their regulation is intimately linked. This review highlights the current information on molecular and biochemical properties of HO-1 and HO-2 and addresses the possible mechanisms for mutual regulatory interactions between the CO- and NO-generating systems.
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Affiliation(s)
- M D Maines
- Department of Biophysics, University of Rochester School of Medicine, New York 14642, USA
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Poulat P, De Champlain J, D'Orléans-Juste P, Couture R. Receptor and mechanism that mediate endothelin- and big endothelin-1-induced phosphoinositide hydrolysis in the rat spinal cord. Eur J Pharmacol 1996; 315:327-34. [PMID: 8982672 DOI: 10.1016/s0014-2999(96)00610-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In rat spinal cord slices, endothelin-1 and endothelin-3 enhanced [3H]inositol phosphate production between 1 nM and 10 microM (endothelin-1 > endothelin-3) while sarafotoxin 6c and the endothelin ETB receptor agonist IRL-1620 (Suc-[Glu9,Ala11,15]endothelin-1-(8-21)) were almost ineffective. BQ-123 (cyclo(D-Trp,D-Asp,L-Pro,D-Val,L-Leu), a selective endothelin ETA receptor antagonist, reduced the endothelin-1- and endothelin-3-induced [3H]inositol phosphate production, with similar inhibition constants (IC50: 16.7 +/- 3.4 and 8.0 +/- 1.6 microM, respectively). The inhibition of endothelin-1 was enhanced when BQ-123 was preincubated for 30 min instead of 15 min. BQ-788 (N-cis-2,6-dimethylpiperidinocarbonyl-L-gamma-methylleucyl-D -1-methoxy- carbonyltryptophanyl-D-Nle), a selective ETB receptor antagonist, did not modify the endothelin-1-induced [3H]inositol phosphate production. Big endothelin-1 (1 nM to 1 microM) was slightly less potent than endothelin-1 in enhancing [3H]inositol phosphate production. This response was sensitive to phosphoramidon and [Phe22]big endothelin-1-(19-37), two inhibitors of endothelin-converting enzyme. Pretreatment of slices with pertussis toxin, indomethacin or PN 200-110 ((-)-isradipine, a dual inhibitor of L- and R-type Ca2+ channels) did not alter the response to 1 microM endothelin-1 while this response was abolished by tetrodotoxin. Finally, endothelin-1 enhanced [3H]inositol phosphate production with an identical EC50 (2.1 nM) in spinal cord slices of Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) although the maximal response was reduced in SHR. These data indicate that endothelins stimulated [3H]inositol phosphate production in the rat spinal cord through the activation of an endothelin ETA receptor that trigger the release of an unidentified neurotransmitter. This effect does not appear to be associated to activation of a Gi/G(o)-type of G-protein, dihydropyridine-sensitive L-type Ca2+ channels or to the production of prostaglandins. Furthermore, the findings support the presence of a phosphoramidon-sensitive endothelin-converting enzyme in the spinal cord.
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Affiliation(s)
- P Poulat
- Department of Physiology, Faculty of Medicine, Université de Montréal, Québec, Canada
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Ea-Kim L, Javellaud J, Oudart N. Reduction of the pressor response to nicotine in the guinea pigs by a histamine (H3) agonist is attenuated by an inhibitor of nitric oxide synthesis. J Cardiovasc Pharmacol 1996; 27:607-13. [PMID: 8847881 DOI: 10.1097/00005344-199604000-00023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We examined whether a histamine (H3)-agonist, (R) alpha-methylhistamine, [(R) alpha-MeHA] reduced the pressor responses induced by nicotine in urethane-anesthetized guinea pigs treated by atropine. Nicotine dose-dependently increased the basal mean arterial pressure (MAP) and the heart rate (HR) of the preparation. Both effects were due to stimulation of sympathetic ganglia, since muscarinic receptors were blocked. Adrenalectomy did not affect either the hypertension or the tachycardia to nicotine. Nicotine (7 micrograms kg-1) evoked a transient hypertension of approximately 30 mm Hg and a tachycardia by approximately 20 beats/min. (R) alpha-MeHA dose-dependently inhibited the increase in mean arterial pressure and the increase in HR to nicotine but not those produced by exogenous norepinephrine (NE). The inhibitory effects of (R) alpha-MeHA were dose-dependently antagonized by the H3-antagonist thioperamide, but not by combined mepyramine/cimetidine. They were also suppressed by a nitric oxide (NO)-synthase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME); this suppression was reversed by L-arginine. Histamine in the presence of mepyramine and cimetidine induced a similar inhibition of the hypertension to nicotine but a less potent inhibition of the tachycardia. These findings indicate that postganglionic noradrenergic nerve fibers are endowed with presynaptic H3-receptors, the stimulation of which inhibits NE release through an NO mechanism.
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Affiliation(s)
- L Ea-Kim
- Laboratoire de Pharmacologie, UFR de Pharmacie, Limoges, France
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Shraga-Levine Z, Sokolovsky M. cGMP formation in rat atrial slices is ligand and endothelin receptor subtype specific. Circ Res 1996; 78:424-30. [PMID: 8593701 DOI: 10.1161/01.res.78.3.424] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Involvement of a cGMP pathway in signal transduction stimulated by endothelins(ETs) and sarafotoxins (SRTXs) was examined in rat atrial slices. These peptides activated different receptor-binding sites (ET-1 and SRTX-b reacted with picomolar binding sites of the ET(A) receptor, and ET-3 and SRTX-c reacted with the nanomolar binding sites of the ET(B) receptor) to produce cGMP. ET-1 and SRTX-b stimulated an increase in cGMP levels via a Ca2+-dependent NO pathway involving a pertussis toxin-insensitive G protein, whereas ET-3 and SRTX-c elevated cGMP levels via a Ca2+-independent CO pathway involving a pertussis toxin-sensitive G protein. These results can best be explained in terms of formation of different ligand-receptor-G-protein complexes. The ligands had no effect on ventricular slices, indicating that these signal transduction mechanisms are unique to the atria.
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Affiliation(s)
- Z Shraga-Levine
- Laboratory of Neurobiochemistry, George S. Wise Faculty of Life Sciences, Tel Aviv University, Israel
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Sokolovsky M. Endothelin receptor heterogeneity, G-proteins, and signaling via cAMP and cGMP cascades. Cell Mol Neurobiol 1995; 15:561-71. [PMID: 8719041 DOI: 10.1007/bf02071317] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
1. The endothelins (ETs) are potent vasoactive peptides which are involved in diverse biological processes, such as contraction, neuromodulation, and neurotransmission, as well as in certain pathophysiological conditions including cardiac and renal failure. 2. The diversity of action of ETs may be attributed to (i) the existence of a number of receptor subtypes, and (ii) the G-protein-mediated activation of different signal transduction pathways. 3. The combined action of these two variables modulates the response, since different receptor subtypes can stimulate and/or inhibit the cAMP and cGMP cascades.
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Affiliation(s)
- M Sokolovsky
- Laboratory of Neurobiochemistry, Tel Aviv University, Israel
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Abstract
The endothelins (ETs) are potent vasoactive peptides that appear to be involved in diverse biological actions, for example, contraction, neuromodulation, and neurotransmission, as well as in various pathophysiological conditions, such as renal and heart failure. The diversity of actions of ETs may be explained in terms of (1) the existence of several receptor subtypes and (2) the activation of different signal transduction pathways. This review summarizes the state of the art in this intensively studied field, with particular focus on structural aspects, receptor heterogeneity, coupling of receptors to G-proteins, and signal transduction mechanisms mediated by the activation of ET-receptors.
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Affiliation(s)
- M Sokolovsky
- Laboratory of Neurobiochemistry, Tel Aviv University, Israel
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