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Djikic T, Vucicevic J, Laurila J, Radi M, Veljkovic N, Xhaard H, Nikolic K. Deciphering Imidazoline Off‐targets by Fishing in the Class A of GPCR field. Mol Inform 2020; 39:e1900165. [DOI: 10.1002/minf.201900165] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 02/20/2020] [Indexed: 12/13/2022]
Affiliation(s)
- Teodora Djikic
- Department of Pharmaceutical ChemistryFaculty of PharmacyUniversity of Belgrade Vojvode Stepe 450 11000 Belgrade Serbia
| | - Jelica Vucicevic
- Department of Pharmaceutical ChemistryFaculty of PharmacyUniversity of Belgrade Vojvode Stepe 450 11000 Belgrade Serbia
| | - Jonne Laurila
- Research Center for Integrative Physiology and Pharmacology, Institute of BiomedicineUniversity of Turku FI-20014 Turun yliopisto, Turku Finland
| | - Marco Radi
- Dipartimento di Scienze degli Alimenti e del FarmacoUniversità degli Studi di Parma Viale delle Scienze, 27/A 43124 Parma Italy
| | - Nevena Veljkovic
- Laboratory for bioinformatics and computational chemistry, Institute of Nuclear Sciences VincaUniversity of Belgrade Mihaila Petrovica Alasa 14 11001 Belgrade Serbia
| | - Henri Xhaard
- Division of Pharmaceutical Chemistry, Drug Research Program, Division of Pharmaceutical Chemistry and Technology, Faculty of PharmacyUniversity of Helsinki P.O. Box 56 FI-00014 Helsinki Finland
| | - Katarina Nikolic
- Department of Pharmaceutical ChemistryFaculty of PharmacyUniversity of Belgrade Vojvode Stepe 450 11000 Belgrade Serbia
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Lehner Z, Stadlbauer K, Brunmair B, Adorjan I, Genov M, Kautzky‐Willer A, Scherer T, Scheinin M, Bauer L, Fürnsinn C. Evidence that the multiflorine-derived substituted quinazolidine 55P0251 augments insulin secretion and lowers blood glucose via antagonism at α 2 -adrenoceptors in mice. Diabetes Obes Metab 2020; 22:290-302. [PMID: 31608542 PMCID: PMC7065191 DOI: 10.1111/dom.13895] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 10/07/2019] [Accepted: 10/08/2019] [Indexed: 11/28/2022]
Abstract
AIMS To investigate the mechanism of action of 55P0251, a novel multiflorine-derived substituted quinazolidine that augments insulin release and lowers blood glucose in rodents, but does not act via mechanisms addressed by any antidiabetic agent in clinical use. MATERIALS AND METHODS Using male mice, we determined the effects of 55P0251 on glucose tolerance, insulin secretion from isolated islets and blood oxygen saturation, including head-to-head comparison of 55P0251 to its inverted enantiomer 55P0250, as well as to other anti-hyperglycaemic multiflorine derivatives discovered in our programme. RESULTS 55P0251 was clearly superior to its inverted enantiomer in the glucose tolerance test (area under the curve: 11.3 mg/kg 55P0251, 1.19 ± 0.04 min*mol/L vs 55P0250, 1.80 ± 0.04 min*mol/L; P < .0001). For insulin release in vitro, this superiority became visible only under concomitant adrenergic background stimulation (glucose-stimulated insulin release, fmol*islet-1 *30 min-1 : without α2 -adrenoceptor agonist: 500 μmol/L 55P0251, 390 ± 34, vs 55P0250, 459 ± 40, nonsignificant; with α2 -adrenoceptor agonist: 250 μmol/L 55P0251, 138 ± 9, vs 55P0250, 21 ± 6; P < .0001). Since receptor binding assays suggested antagonism at α2A -adrenoceptors as a potential mechanism of action, we measured oxygen saturation in capillary blood from the tail as a surrogate of vasoconstriction, which supported α2 -antagonistic action in vivo (90 mg/kg 55P0251, 83 ± 3%, vs 55P0250, 57 ± 3%; P < .0001). Lack of association between glucose-lowering activities and α2A -adrenoceptor binding affinity arising from comparison of multiflorine derivatives was attributed to differences in their pharmacokinetic properties. CONCLUSIONS Our findings suggest that 55P0251 and related multiflorine derivatives are to be categorized as α2 -adrenoceptor antagonists with potential to lower blood glucose by blocking α2A -adrenoceptors on pancreatic β cells.
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Affiliation(s)
- Zsuzsanna Lehner
- Division of Endocrinology and Metabolism, Department of Medicine IIIMedical University of ViennaViennaAustria
| | - Karin Stadlbauer
- Division of Endocrinology and Metabolism, Department of Medicine IIIMedical University of ViennaViennaAustria
| | - Barbara Brunmair
- Division of Endocrinology and Metabolism, Department of Medicine IIIMedical University of ViennaViennaAustria
| | | | | | - Alexandra Kautzky‐Willer
- Division of Endocrinology and Metabolism, Department of Medicine IIIMedical University of ViennaViennaAustria
| | - Thomas Scherer
- Division of Endocrinology and Metabolism, Department of Medicine IIIMedical University of ViennaViennaAustria
| | - Mika Scheinin
- Institute of BiomedicineUniversity of TurkuTurkuFinland
| | | | - Clemens Fürnsinn
- Division of Endocrinology and Metabolism, Department of Medicine IIIMedical University of ViennaViennaAustria
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Lehner Z, Stadlbauer K, Adorjan I, Rustenbeck I, Belz M, Fenzl A, de Cillia VAM, Gruber D, Bauer L, Frobel K, Brunmair B, Luger A, Fürnsinn C. Mechanisms of antihyperglycaemic action of efaroxan in mice: time for reappraisal of α2A-adrenergic antagonism in the treatment of type 2 diabetes? Diabetologia 2012; 55:3071-82. [PMID: 22898767 DOI: 10.1007/s00125-012-2679-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 07/20/2012] [Indexed: 10/28/2022]
Abstract
AIMS/HYPOTHESIS Inspired by recent speculation about the potential utility of α(2A)-antagonism in the treatment of type 2 diabetes, the study examined the contribution of α(2)-antagonism vs other mechanisms to the antihyperglycaemic activity of the imidazoline (±)-efaroxan. METHODS Effects of the racemate and its pure enantiomers on isolated pancreatic islets and beta cells in vitro, as well as on hyperglycaemia in vivo, were investigated in a comparative manner in mice. RESULTS In isolated perifused islets, the two enantiomers of efaroxan were equally potent in counteracting inhibition of insulin release by the ATP-dependent K(+) (K(ATP)) channel-opener diazoxide but (+)-efaroxan, the presumptive carrier of α(2)-antagonistic activity, was by far superior in counteracting inhibition of insulin release by the α(2)-agonist UK14,304. In vivo, (+)-efaroxan improved oral glucose tolerance at 100-fold lower doses than (-)-efaroxan and, in parallel with observations made in vitro, was more effective in counteracting UK14,304-induced than diazoxide-induced hyperglycaemia. The antihyperglycaemic activity of much higher doses of (-)-efaroxan was associated with an opposing pattern (i.e. with stronger counteraction of diazoxide-induced than UK14,304-induced hyperglycaemia), which implicates a different mechanism of action. CONCLUSIONS/INTERPRETATION The antihyperglycaemic potency of (±)-efaroxan in mice is almost entirely due to α(2)-antagonism, but high doses can also lower blood glucose via another mechanism. Our findings call for reappraisal of the possible clinical utility of α(2A)-antagonistic compounds in recently identified subpopulations of patients in which a congenitally higher level of α(2A)-adrenergic activation contributes to the development and pathophysiology of type 2 diabetes.
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Affiliation(s)
- Z Lehner
- Division of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria
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Morgan NG. Section Review: Oncologic, Endocrine and Metabolic Adrenoceptors and imidazoline binding sites in the endocrine pancreas as targets for anti-hyperglycaemic drugs. Expert Opin Investig Drugs 2008. [DOI: 10.1517/13543784.3.6.561] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Crane L, Anastassiadou M, El Hage S, Stigliani JL, Baziard-Mouysset G, Payard M, Leger JM, Bizot-Espiard JG, Ktorza A, Caignard DH, Renard P. Design and synthesis of novel imidazoline derivatives with potent antihyperglycemic activity in a rat model of type 2 diabetes. Bioorg Med Chem 2006; 14:7419-33. [PMID: 16889967 DOI: 10.1016/j.bmc.2006.07.026] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2006] [Revised: 07/06/2006] [Accepted: 07/10/2006] [Indexed: 10/24/2022]
Abstract
Imidazoline derivatives have been reported to show antihyperglycemic activity in vivo. In the present study, we first showed that there was no correlation between the in vivo antidiabetic activity and the in vitro affinities for the I1/I2 binding sites for several substituted aryl imidazolines. Among these compounds, 2-(alpha-cyclohexyl-benzyl)-4,5-dihydro-1H-imidazole 2 exhibited potent antihyperglycemic properties. It was then chosen as lead compound. Thirty-six new derivatives were synthesized by replacing the cyclohexyl/benzyl group by various cyclic systems or the imidazoline ring by isosteric heterocycles. These compounds were evaluated in vivo for their antihyperglycemic activity using an oral glucose tolerance test (OGTT) in a rat model of type-2 diabetes obtained by giving a single intravenous (iv) injection of a low dose of streptozotocin to rats (STZ rats) and in normal rats. Nine compounds with an imidazoline moiety, possibly substituted by a methyl group, had a potent effect on the glucose tolerance in normal or STZ-diabetic rats, after an oral (po) administration of the test compound at a dose of 30 or 10 mg kg(-1), without any hypoglycemia. Replacement of the imidazoline ring by isosteric heterocycles resulted in a total loss of activity.
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Affiliation(s)
- Louis Crane
- Université Toulouse III, Faculté des Sciences Pharmaceutiques, Laboratoire de Chimie Pharmaceutique, F-31062 Toulouse Cedex 09, France
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Velliquette RA, Ernsberger P. Contrasting Metabolic Effects of Antihypertensive Agents. J Pharmacol Exp Ther 2003; 307:1104-11. [PMID: 14557373 DOI: 10.1124/jpet.103.054221] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hypertension often coexists with hyperlipidemia, insulin resistance, and glucose intolerance, a comorbidity known as metabolic syndrome X. Different antihypertensives have mixed effects on these associated abnormalities. We compared three antihypertensives in the spontaneously hypertensive obese rat model of syndrome X. Moxonidine (4 mg/kg), an imidazoline and alpha2-adrenergic agonist, alpha-methyldopa (200 mg/kg), an alpha2-adrenergic agonist, or the vasodilator hydralazine (10 mg/kg) was given orally for 15 d. All three agents lowered blood pressure equally. Moxonidine significantly reduced fasting plasma insulin, glucagon, cholesterol, triglycerides, and free fatty acids (FFA) compared with untreated controls. In contrast, syndrome X markers were not affected by alpha-methyldopa treatment, and hydralazine reduced only glucagon and FFA. Relative to untreated controls, moxonidine improved glucose tolerance as shown by reduced glucose area under the curve (AUC) (13.6 +/- 2.4 versus 42.5 +/- 9.9 g x min/dl). Insulin AUC was increased (7.4 +/- 0.9 versus 3.9 +/- 1.8 microg x min/ml) as was the plasma C-peptide response to the glucose load. In contrast, alpha-methyldopa and hydralazine worsened glucose tolerance (68 +/- 26 and 110 +/- 21 g x min/ml, respectively) and significantly reduced insulin AUC (2.5 +/- 0.8 and -2.3 +/- 1.0 microg x min/ml, respectively) compared with controls. Moxonidine reduced but alpha-methyldopa and hydralazine elevated glucagon levels after the glucose load. Contrary to the "hemodynamic hypothesis" for the metabolic actions of antihypertensives, which predicts roughly equal benefits, only moxonidine had a positive impact on comorbidities. This unique action suggests a role for direct stimulation of imidazoline receptors.
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Affiliation(s)
- Rodney A Velliquette
- Department of Nutrition, Case Western Reserve University School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106-4906, USA
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Bruban V, Feldman J, Greney H, Dontenwill M, Schann S, Jarry C, Payard M, Boutin J, Scalbert E, Pfeiffer B, Renard P, Vanhoutte P, Bousquet P. Respective contributions of alpha-adrenergic and non-adrenergic mechanisms in the hypotensive effect of imidazoline-like drugs. Br J Pharmacol 2001; 133:261-6. [PMID: 11350862 PMCID: PMC1572786 DOI: 10.1038/sj.bjp.0704080] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The hypotensive effect of imidazoline-like drugs, such as clonidine, was first attributed to the exclusive stimulation of central alpha2-adrenoceptors (alpha2ARs). However, a body of evidence suggests that non-adrenergic mechanisms may also account for this hypotension. This work aims (i) to check whether imidazoline-like drugs with no alpha2-adrenergic agonist activity may alter blood pressure (BP) and (ii) to seek a possible interaction between such a drug and an alpha2ARs agonist alpha-methylnoradrenaline (alpha-MNA). We selected S23515 and S23757, two imidazoline-like drugs with negligible affinities and activities at alpha2ARs but with high affinities for non-adrenergic imidazoline binding sites (IBS). S23515 decreased BP dose-dependently (-27+/-5% maximal effect) when administered intracisternally (i.c.) to anaesthetized rabbits. The hypotension induced by S23515 (100 microg kg(-1) i.c.) was prevented by S23757 (1 mg kg(-1) i.c.) and efaroxan (10 microg kg(-1) i.c.), while these compounds, devoid of haemodynamic action by themselves, did not alter the hypotensive effect of alpha-MNA (3 and 30 microg kg(-1) i.c.). Moreover, the alpha2ARs antagonist rauwolscine (3 microg kg(-1) i.c.) did not prevent the effect of S23515. Finally, whilst 3 microg kg(-1) of S23515 or 0.5 microg kg(-1) of alpha-MNA had weak hypotensive effects, the sequential i.c. administration of these two drugs induced a marked hypotension (-23+/-2%). These results indicate that an imidazoline-like drug with no alpha2-adrenergic properties lowers BP and interacts synergistically with an alpha(ARs agonist.
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Affiliation(s)
- Véronique Bruban
- Laboratoire de Neurobiologie et Pharmacologie Cardiovasculaire, Faculté de Médecine, Université Louis Pasteur, 11 rue Humann, 67000 Strasbourg, France
| | - Josiane Feldman
- Laboratoire de Neurobiologie et Pharmacologie Cardiovasculaire, Faculté de Médecine, Université Louis Pasteur, 11 rue Humann, 67000 Strasbourg, France
| | - Hugues Greney
- Laboratoire de Neurobiologie et Pharmacologie Cardiovasculaire, Faculté de Médecine, Université Louis Pasteur, 11 rue Humann, 67000 Strasbourg, France
| | - Monique Dontenwill
- Laboratoire de Neurobiologie et Pharmacologie Cardiovasculaire, Faculté de Médecine, Université Louis Pasteur, 11 rue Humann, 67000 Strasbourg, France
| | - Stephan Schann
- Laboratoire de Neurobiologie et Pharmacologie Cardiovasculaire, Faculté de Médecine, Université Louis Pasteur, 11 rue Humann, 67000 Strasbourg, France
| | - Christian Jarry
- Laboratoire de Chimie Physique, Faculté des Sciences Pharmaceutiques, Université Bordeaux 2, 146 rue Leo Saignat, 33076 Bordeaux cedex, France
| | - Marc Payard
- Laboratoire de Chimie Pharmaceutique, Faculté de Pharmacie, 35 chemin des Maraîchers, 31400 Toulouse, France
| | - Jean Boutin
- Institut de Recherches Internationales Servier, 6 place des Pléiades, 92415 Courbevoie cedex, France
| | - Elizabeth Scalbert
- Institut de Recherches Internationales Servier, 6 place des Pléiades, 92415 Courbevoie cedex, France
| | - Bruno Pfeiffer
- Institut de Recherches Internationales Servier, 6 place des Pléiades, 92415 Courbevoie cedex, France
| | - Pierre Renard
- Institut de Recherches Internationales Servier, 6 place des Pléiades, 92415 Courbevoie cedex, France
| | - Paul Vanhoutte
- Institut de Recherches Internationales Servier, 6 place des Pléiades, 92415 Courbevoie cedex, France
| | - Pascal Bousquet
- Laboratoire de Neurobiologie et Pharmacologie Cardiovasculaire, Faculté de Médecine, Université Louis Pasteur, 11 rue Humann, 67000 Strasbourg, France
- Author for correspondence:
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Abstract
1. Naloxone, which is often regarded as a pure opioid antagonist, produces effects similar to those produced by morphine. 2. In conscious rabbits implanted with an intracerebroventricular (i.c.v.) cannula, naloxone, whether given intravenously (1 mg/kg) or i.c.v. (1-100 microg), produced a significant rise in blood glucose levels. 3. Hyperglycaemia in response to naloxone (1 mg/kg, i.v., or 100 microg, i.c.v.) was not influenced by the selective alpha1-adrenoceptor antagonist WB-4101 given either i.v. (50 microg) or i.c.v. (5 microg). 4. Hyperglycaemia in response to naloxone (1 mg/kg, i.v., or 100 microg, i.c.v.) was completely blocked by pretreatment with the alpha2-adrenoceptor antagonist yohimbine (1 mg/kg, i.v., or 100 microg, i.c.v.). However, hyperglycaemia to i.c.v. naloxone (100 microg) was not influenced by i.v. yohimbine (1 mg/kg). 5. Because naloxone behaves like morphine and produces hyperglycaemia in conscious rabbits, the drug may have an appreciable agonist activity and the hyperglycaemic response to naloxone is principally mediated via alpha2- but not alpha1-adrenoceptors.
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Affiliation(s)
- H A Abouazra
- Department of Pharmacology, Faculty of Medicine, Al-Arab Medical University, Benghazi, Libya.
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Chan SL, Mourtada M, Morgan NG. Characterization of a KATP channel-independent pathway involved in potentiation of insulin secretion by efaroxan. Diabetes 2001; 50:340-7. [PMID: 11272145 DOI: 10.2337/diabetes.50.2.340] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Efaroxan, like several other imidazoline reagents, elicits a glucose-dependent increase in insulin secretion from pancreatic beta-cells. This response has been attributed to efaroxan-mediated blockade of KATP channels, with the subsequent gating of voltage-sensitive calcium channels. However, increasing evidence suggests that, at best, this mechanism can account for only part of the secretory response to the imidazoline. In support of this, we now show that efaroxan can induce functional changes in the secretory pathway of pancreatic beta-cells that are independent of KATP channel blockade. In particular, efaroxan was found to promote a sustained sensitization of glucose-induced insulin release that persisted after removal of the drug and to potentiate Ca2+-induced insulin secretion from electropermeabilized islets. To investigate the mechanisms involved, we studied the effects of the efaroxan antagonist KU14R. This agent is known to selectively inhibit insulin secretion induced by efaroxan, without altering the secretory response to glucose or KCl. Surprisingly, however, KU14R markedly impaired the potentiation of insulin secretion mediated by agents that raise cAMP, including the adenylate cyclase activator, forskolin, and the phosphodiesterase inhibitor isobutylmethyl xanthine (IBMX). These effects were not accompanied by any reduction in cAMP levels, suggesting an antagonistic action of KU14R at a more distal point in the pathway of potentiation. In accord with our previous work, islets that were exposed to efaroxan for 24 h became selectively desensitized to this agent, but they still responded normally to glucose. Unexpectedly, however, the ability of either forskolin or IBMX to potentiate glucose-induced insulin secretion was severely impaired in these islets. By contrast, the elevation of cAMP was unaffected by culture of islets with efaroxan. Taken together, the data suggest that, in addition to effects on the KATP channel, imidazolines also interact with a more distal component that is crucial to the potentiation of insulin secretion. This component is not required for Ca2+-dependent secretion per se but is essential to the mechanism by which cAMP potentiates insulin release. Overall, the results indicate that the actions of efaroxan at this distal site may be more important for control of insulin secretion than its effects on the KATP channel.
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Affiliation(s)
- S L Chan
- Institute of Cell Signalling, University of Nottingham, UK
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Rascol O, Sieradzan K, Peyro-Saint-Paul H, Thalamas C, Brefel-Courbon C, Senard JM, Ladure P, Montastruc JL, Lees A. Efaroxan, an alpha-2 antagonist, in the treatment of progressive supranuclear palsy. Mov Disord 1998; 13:673-6. [PMID: 9686773 DOI: 10.1002/mds.870130411] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
We have tested, in a prospective randomized, double-blind, placebo-controlled, crossover, 12-week study, the effects of 2 mg efaroxan, a potent alpha-2 antagonist, given three times per day to 14 patients with progressive supranuclear palsy. Efaroxan did not induce any significant change on any motor assessment criteria. The present data do not confirm the assumption that the blockade of alpha-2 receptors might be a useful pharmacologic strategy to improve patients with progressive supranuclear palsy.
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Affiliation(s)
- O Rascol
- Department of Clinical Pharmacology, University Hospital, Toulouse, France
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11
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Mourtada M, Smith SA, Morgan NG. Insulin secretagogues with an imidazoline structure inhibit arginine-induced secretion from isolated glucagon secretion from isolated rat islets of Langerhans. Biochem Biophys Res Commun 1997; 236:162-6. [PMID: 9223445 DOI: 10.1006/bbrc.1997.6922] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
It is well documented that imidazoline compounds such as efaroxan and phentolamine act as potent insulin secretagogues both in vivo and in vitro, an effect which is mediated principally by blockade of ATP-sensitive potassium channels in the pancreatic B-cell. However, little is known about the effects of these drugs on the secretion of other pancreatic hormones and, in the present work, we have investigated the effects of selective imidazoline compounds on glucagon release from isolated rat islets of Langerhans. None of several imidazoline compounds tested (efaroxan, phentolamine, idazoxan, antazoline) affected glucagon secretion from islets incubated with 4 mM glucose. However, when the rate of glucagon release was stimulated by L-arginine (20 mM) efaroxan caused a rapid, sustained and dose-dependent inhibition of the secretory response (EC50 approximately 30 microM). This effect was seen under both static incubation and islet perifusion conditions. Antazoline and phentolamine also inhibited arginine-induced glucagon secretion, whereas idazoxan (an imidazoline which does not affect insulin secretion) failed to alter glucagon release. The inhibitory effects of imidazolines on glucagon release were not secondary to changes in insulin secretion. Taken together, the results indicate that pancreatic A-cells express functional imidazoline receptors which can regulate the secretory activity of the cells.
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Affiliation(s)
- M Mourtada
- Cellular Pharmacology Group, Department of Biological Sciences, Keele University, Staffs, United Kingdom
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Morgan NG, Chan SL, Brown CA, Tsoli E. Characterization of the imidazoline binding site involved in regulation of insulin secretion. Ann N Y Acad Sci 1995; 763:361-73. [PMID: 7677348 DOI: 10.1111/j.1749-6632.1995.tb32424.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- N G Morgan
- Department of Biological Sciences, Keele University, Staffs, UK
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Annotated References. Expert Opin Investig Drugs 1994. [DOI: 10.1517/13543784.3.6.673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Affiliation(s)
- B Hulin
- Pfizer Central Research, Groton, CT 06340
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