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Fehér Á, Tóth VE, Al-Khrasani M, Balogh M, Lázár B, Helyes Z, Gyires K, Zádori ZS. Analysing the effect of I 1 imidazoline receptor ligands on DSS-induced acute colitis in mice. Inflammopharmacology 2016; 25:107-118. [PMID: 27873165 DOI: 10.1007/s10787-016-0299-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 11/13/2016] [Indexed: 12/28/2022]
Abstract
Imidazoline receptors (IRs) have been recognized as promising targets in the treatment of numerous diseases; and moxonidine and rilmenidine, agonists of I1-IRs, are widely used as antihypertensive agents. Some evidence suggests that IR ligands may induce anti-inflammatory effects acting on I1-IRs or other molecular targets, which could be beneficial in patients with inflammatory bowel disease (IBD). On the other hand, several IR ligands may stimulate also alpha2-adrenoceptors, which were earlier shown to inhibit, but in more recent studies to rather aggravate colitis. Hence, this study aimed to analyse for the first time the effect of various I1-IR ligands on intestinal inflammation. Colitis was induced in C57BL/6 mice by adding dextran sulphate sodium (DSS) to the drinking water for 7 days. Mice were treated daily with different IR ligands: moxonidine and rilmenidine (I1-IR agonists), AGN 192403 (highly selective I1-IR ligand, putative antagonist), efaroxan (I1-IR antagonist), as well as with the endogenous IR agonists agmatine and harmane. It was found that moxonidine and rilmenidine at clinically relevant doses, similarly to the other IR ligands, do not have a significant impact on the macroscopic and histological signs of DSS-evoked inflammation. Likewise, colonic myeloperoxidase and serum interleukin-6 levels remained unchanged in response to these agents. Thus, our study demonstrates that imidazoline ligands do not influence significantly the severity of DSS-colitis in mice and suggest that they probably neither affect the course of IBD in humans. However, the translational value of these findings needs to be verified with other experimental colitis models and human studies.
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Affiliation(s)
- Ágnes Fehér
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary
| | - Viktória E Tóth
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary
| | - Mahmoud Al-Khrasani
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary
| | - Mihály Balogh
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary
| | - Bernadette Lázár
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary
| | - Zsuzsanna Helyes
- Department of Pharmacology and Pharmacotherapy, Szentagothai Research Centre and MTA-NAP B Chronic Pain Research Group, University of Pécs, Pécs, Hungary
| | - Klára Gyires
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary
| | - Zoltán S Zádori
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary.
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Zádori ZS, Tóth VE, Fehér Á, Philipp K, Németh J, Gyires K. Evidence for the gastric cytoprotective effect of centrally injected agmatine. Brain Res Bull 2014; 108:51-9. [DOI: 10.1016/j.brainresbull.2014.07.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 07/19/2014] [Accepted: 07/31/2014] [Indexed: 02/07/2023]
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3
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Zádori ZS, Fehér Á, Al-Khrasani M, Lackó E, Tóth VE, Brancati SB, Hein L, Mátyus P, Gyires K. Imidazoline versus alpha2-adrenoceptors in the control of gastric motility in mice. Eur J Pharmacol 2013; 705:61-7. [DOI: 10.1016/j.ejphar.2013.02.043] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2012] [Revised: 02/16/2013] [Accepted: 02/24/2013] [Indexed: 10/27/2022]
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Ishikawa T, Kamisaki Y, Omodani H, Houi N, Maeyama K, Watanabe T, Itoh T. Inhibitory Effects of Histamine H2-Antagonists on Forskolin-Stimulated Acid Production in Isolated Parietal Cells. ACTA ACUST UNITED AC 2012. [DOI: 10.1007/bf03259400] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Molderings GJ, Haenisch B. Agmatine (decarboxylated l-arginine): Physiological role and therapeutic potential. Pharmacol Ther 2012; 133:351-65. [DOI: 10.1016/j.pharmthera.2011.12.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 12/05/2011] [Indexed: 01/14/2023]
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6
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Chung S, Kwon S, Kim Y, Ahn D, Lee Y, Nam T. Inhibition by clonidine of the carbachol-induced tension development and nonselective cationic current in guinea pig ileal myocytes. JAPANESE JOURNAL OF PHARMACOLOGY 2001; 87:125-33. [PMID: 11700011 DOI: 10.1254/jjp.87.125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Effects of clonidine, an imidazoline derivative as well as alpha2-adrenoceptor agonist, on carbachol (CCh)-evoked contraction in guinea pig ileal smooth muscle were studied using isometric tension recording. To investigate the cellular mechanisms of the inhibitory effect of clonidine, its effects on CCh-evoked nonselective cationic current (I(CCh)), voltage-dependent Ca2+ current (I(Ca)) and voltage-dependent K+ current (I(K)) was also studied using patch-clamp recording techniques in single ileal cells. Clonidine inhibited the contraction evoked by CCh (1 microM) in a concentration-dependent manner with an IC50 valve of 61.7 +/- 2.5 microM. High K+ (40 mM)-evoked contraction was only slightly inhibited even when clonidine was used at 300 microM. Externally applied clonidine inhibited I(CCh) dose-dependently with an IC50 of 42.0 +/- 2.6 microM. When applied internally via patch pipettes, clonidine was without effect. An I(CCh)-like current induced by GTPgammaS was also inhibited by bath application of clonidine. None of KU14R and BU224, both imidazoline receptor blockers, and yohimbine, an alpha2-adrenergic blocker, significantly affects the inhibitory effect of clonidine on I(CCh). Clonidine (300 microM) only slightly decreased membrane currents flowing through voltage-gated Ca2+ channels or K+ channels. These data indicate that clonidine relaxes smooth muscle contraction produced by muscarinic receptor activation and suggest that the effect of clonidine seems due mainly to inhibition of I(CCh) via acting directly on the involved cationic channel.
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Affiliation(s)
- S Chung
- Department of Physiology, College of Medicine, Yonsei University, Seoul, Korea
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Raasch W, Schäfer U, Chun J, Dominiak P. Biological significance of agmatine, an endogenous ligand at imidazoline binding sites. Br J Pharmacol 2001; 133:755-80. [PMID: 11454649 PMCID: PMC1572857 DOI: 10.1038/sj.bjp.0704153] [Citation(s) in RCA: 144] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- W Raasch
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany.
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Molderings GJ, Burian M, Menzel S, Donecker K, Homann J, Nilius M, Göthert M. Imidazoline recognition sites and stomach function. Ann N Y Acad Sci 1999; 881:332-43. [PMID: 10415933 DOI: 10.1111/j.1749-6632.1999.tb09377.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Radioligand binding experiments carried out in cell membranes from rat and human stomach revealed the existence of non-adrenoceptor [3H]clonidine and [3H]idazoxan binding sites and of [3H]DTG (1,2-di-(2-tolyl)guanidine) binding sites. In rat stomach, specific binding was inhibited by imidazolines and guanidines and by non-imidazoline sigma-site ligands, respectively, at different rank orders of affinity, suggesting the existence of non-I1/non-I2 [3H]clonidine binding sites, I2-imidazoline binding sites as well as sigma 2-like-sites. These sites are not directly related to a postsynaptic contractile effect on rat gastric smooth muscle or to acid release from isolated gastric glands. Finally, we demonstrated that the gastric pathogen Helicobacter pylori is able to form and to release the endogenous imidazoline receptor ligand agmatine and that considerable amounts of agmatine are present in human gastric juice. The quantities of agmatine were higher in gastric juice from H. pylori-positive than H. pylori-negative patients.
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Affiliation(s)
- G J Molderings
- Institute of Pharmacology and Toxicology, University of Bonn, Germany.
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Molderings GJ, Donecker K, Göthert M. Characterization of non-adrenergic [3H]clonidine binding sites in rat stomach: high affinity of imidazolines, guanidines and sigma ligands. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 1995; 351:561-4. [PMID: 7643920 DOI: 10.1007/bf00171049] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We have identified and characterized non-adrenergic [3H]clonidine binding sites in rat stomach. The binding of [3H]clonidine was rapid, reversible, partly specific (as defined by cirazoline 0.1 nmol/l), saturable and of high affinity. The specific binding of [3H]clonidine to rat stomach membranes was concentration-dependently inhibited by various imidazolines and guanidines including the sigma site ligand 1,2-di-(2-tolyl)guanidine (DTG), by the butyrophenone derivative (+)-3-PPP[(R)-3-(3-hydroxyphenyl)-N-propylpiperidine]; the latter two compounds are also known to exhibit affinity for sigma sites. In contrast, rauwolscine, histamine, ranitidine and the non-hydrolysable GTP-analogue Gpp(NH)p (5' guanylylimidodiphosphate) did not, or with negligible affinity, inhibit [3H]clonidine binding. In most cases, the competition curves were best fitted to a two-site model. The rank order of affinity for the high affinity site (in a few cases for a single detectable site) was as follows: cirazoline > idazoxan > or = DTG > (+)-3-PPP > chlonidine > guanabenz > haloperidol. This rank order is not compatible with the pharmacological properties of either I1- or I2-imidazoline binding sites. However, the ability of haloperidol, (+)-3-PPP and DTG to displace [3H]clonidine (the latter two with high affinity) suggests that the [3H] clonidine binding sites in rat stomach may be related to sigma-like sites.
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Affiliation(s)
- G J Molderings
- Institut für Pharmakologie und Toxikologie der Rheinischen Friedrich-Wilhelms-Universität Bonn, Germany
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Kamisaki Y, Ishikawa T, Takao Y, Omodani H, Kuno N, Itoh T. Binding of [3H]p-aminoclonidine to two sites, alpha 2-adrenoceptors and imidazoline binding sites: distribution of imidazoline binding sites in rat brain. Brain Res 1990; 514:15-21. [PMID: 2162708 DOI: 10.1016/0006-8993(90)90430-j] [Citation(s) in RCA: 89] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Binding sites labeled by [3H]p-aminoclonidine [( 3H]PAC) were investigated by the competitive analysis with imidazoline and non-imidazoline derivatives. Phenylethylamine derivatives displaced only the part of specific sites for [3H]PAC, which was considered as alpha 2-adrenoceptor, whereas imidazoline derivatives, such as clonidine and tolazoline, competed for a further specific binding of [3H]PAC to the non-adrenergic sites, in addition to the alpha 2-adrenoceptor. Because the non-adrenergic sites were specific for the imidazoline structure, they were termed imidazoline sites. The imidazoline sites were not distributed uniformly among rat brain regions. In striatum, hippocampus and medulla oblongata, they occupied 39.6, 33.0 and 36.5% of the specific binding of [3H]PAC, respectively. Saturation isotherms revealed that Kd and Bmax of imidazoline sites for [3H]PAC were 3.09 +/- 0.59 nM, 27.4 +/- 1.7 fmol/mg protein and 2.23 +/- 0.29 nM, 21.0 +/- 1.5 fmol/mg protein in striatum and hippocampus, respectively. Because imidazoline binding sites also displayed weak affinities for imidazole compounds, such as histamine and cimetidine, the imidazoline site may be a subtype of histamine H2-receptor.
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Affiliation(s)
- Y Kamisaki
- Department of Clinical Pharmacology, Tottori University School of Medicine, Yonago, Japan
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Parini A, Coupry I, Graham RM, Uzielli I, Atlas D, Lanier SM. Characterization of an imidazoline/guanidinium receptive site distinct from the α2-adrenergic receptor. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)80147-8] [Citation(s) in RCA: 96] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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12
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Ishikawa T, Kamisaki Y, Itoh T. Pharmacological properties of the hydroxylated histamine, (+/-)-4(5)-(2-amino-1-hydroxyethyl)-imidazole. AGENTS AND ACTIONS 1989; 26:261-6. [PMID: 2544085 DOI: 10.1007/bf01967288] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The pharmacological effects of the beta-hydroxylated histamine, 4(5)-(2-amino-1-hydroxyethyl)-imidazole, on smooth muscle contraction of the ileum (H1-receptor activity) and gastric acid secretion (H2-receptor activity) of the guinea-pig were investigated and compared with those of histamine. Although beta-hydroxy histamine contracted the ileum with the same maximal response as histamine, the concentration response curve was shifted to the right by approximately three orders of magnitude. At submaximal concentrations, co-administration of beta-hydroxy histamine with histamine revealed only additive effects. This H1-activity was competitively inhibited by diphenhydramine. Similarly, the hydroxylated analogue also increased intracellular cyclic AMP level and [14C] aminopyrine accumulation as a marker of acid secretion in the parietal cells. However, the EC50 was approximately ten fold that of histamine. This H2-receptor activity was inhibited completely by cimetidine. These results suggest that beta-hydroxy histamine possesses nearly full intrinsic activities at both H1 and H2-receptors and that the introduction of a hydroxyl group at the beta-carbon reduces and dissociates these activities.
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Affiliation(s)
- T Ishikawa
- Department of Clinical Pharmacology, Tottori University School of Medicine, Yonago, Japan
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