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Nieto CT, Manchado A, Belda L, Diez D, Garrido NM. 2-Phenethylamines in Medicinal Chemistry: A Review. MOLECULES (BASEL, SWITZERLAND) 2023; 28:molecules28020855. [PMID: 36677913 PMCID: PMC9864394 DOI: 10.3390/molecules28020855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/10/2023] [Accepted: 01/11/2023] [Indexed: 01/19/2023]
Abstract
A concise review covering updated presence and role of 2-phenethylamines in medicinal chemistry is presented. Open-chain, flexible alicyclic amine derivatives of this motif are enumerated in key therapeutic targets, listing medicinal chemistry hits and appealing screening compounds. Latest reports in discovering new bioactive 2-phenethylamines by research groups are covered too.
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2
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Huang R, Tamalunas A, Waidelich R, Strittmatter F, Stief CG, Hennenberg M. Antagonism of α 1-adrenoceptors by β 3-adrenergic agonists: Structure-function relations of different agonists in prostate smooth muscle contraction. Biochem Pharmacol 2022; 202:115148. [PMID: 35716783 DOI: 10.1016/j.bcp.2022.115148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 06/09/2022] [Accepted: 06/10/2022] [Indexed: 11/29/2022]
Abstract
Effects of β3-adrenergic agonists on prostate smooth muscle contraction are poorly characterized, although mirabegron is used for treatment of lower urinary tract symptoms. Off-target effects of several β3-adrenergic agonists include antagonism of α1-adrenoceptors. Proposed, but unconfirmed explanations include phenylethanolamine backbones, found in some β3-adrenergic agonists and imparting interaction with catecholamine binding pockets of adrenoceptors. Here, we examined effects of β3-adrenergic agonists on contractions of human prostate tissues, including ZD7114 (without phenylethanolamine moiety), ZD2079 (phenylethanolamine backbone), BRL37344 and CL316243 (chloride-substituted phenylethanolamine deriatives). Prostate tissues were obtained from radical prostatectomy. Contractions by α1-adrenergic agonists and electric field stimulation (EFS) were studied in an organ bath. ZD7114 (10 µM) right-shifted concentration responses curves for α1-adrenergic agonists, resulting in increased EC50 values for phenylephrine, methoxamine and noradrenaline up to one magnitude, without affecting Emax values. ZD7114 (10 µM) inhibited EFS-induced contractions, resulting in reduced Emax values. All effects of ZD7114 were resistant to the β3-adrenergic antagonist L-748337, including increases in EC50 values for α1-adrenergic agonists, up to more than two magnitudes. Using 10 µM, neither ZD2079, BRL37344 or CL316243 affected α1-adrenergic or EFS-induced contractions. At escalated concentrations, BRL37344 (200 µM) right-shifted concentration response curves for phenylephrine, increased EC50 values for phenylephrine, and inhibited EFS-induced contractions, while CL316243 (300 µM) did not affect phenylephrine- or EFS-induced contractions. In conclusion, phenylethanolamine backbones are not decisive to impart α1-adrenoceptor antagonism to β3-agonists. Effects of β3-adrenergic agonists on prostate smooth muscle contraction are limited to off-target effects, including α1-adrenoceptor antagonism by ZD7114 and BRL37344.
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Affiliation(s)
- Ru Huang
- Department of Urology, University Hospital Munich, LMU Munich, Munich, Germany
| | - Alexander Tamalunas
- Department of Urology, University Hospital Munich, LMU Munich, Munich, Germany
| | - Raphaela Waidelich
- Department of Urology, University Hospital Munich, LMU Munich, Munich, Germany
| | - Frank Strittmatter
- Department of Urology, University Hospital Munich, LMU Munich, Munich, Germany
| | - Christan G Stief
- Department of Urology, University Hospital Munich, LMU Munich, Munich, Germany
| | - Martin Hennenberg
- Department of Urology, University Hospital Munich, LMU Munich, Munich, Germany.
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Ozkan MH, Uma S. β-adrenergic Receptor Blocker ICI 118,551 Selectively Increases Intermediate-Conductance Calcium-Activated Potassium Channel (IKCa
)-Mediated Relaxations in Rat Main Mesenteric Artery. Basic Clin Pharmacol Toxicol 2018; 122:570-576. [DOI: 10.1111/bcpt.12949] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 12/07/2017] [Indexed: 11/27/2022]
Affiliation(s)
- Melike Hacer Ozkan
- Department of Pharmacology; Faculty of Pharmacy; Hacettepe University; Ankara Turkey
| | - Serdar Uma
- Department of Pharmacology; Faculty of Pharmacy; Hacettepe University; Ankara Turkey
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4
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Neumann V, Knies R, Seidinger A, Simon A, Lorenz K, Matthey M, Breuer J, Wenzel D. The β
2
agonist terbutaline specifically decreases pulmonary arterial pressure under normoxia and hypoxia via a adrenoceptor antagonism. FASEB J 2018; 32:2519-2530. [DOI: 10.1096/fj.201700684rr] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Vanessa Neumann
- Life and Brain Center Institute of Physiology I Medical Faculty University of Bonn Bonn Germany
| | - Ralf Knies
- Department of Pediatric Cardiology Pediatric Heart Center University Clinic Bonn Bonn Germany
| | - Alexander Seidinger
- Life and Brain Center Institute of Physiology I Medical Faculty University of Bonn Bonn Germany
| | - Annika Simon
- Life and Brain Center Institute of Physiology I Medical Faculty University of Bonn Bonn Germany
| | - Kristina Lorenz
- Leibniz‐Institut für Analytische Wissenschaften (ISAS) Dortmund Germany
| | - Michaela Matthey
- Life and Brain Center Institute of Physiology I Medical Faculty University of Bonn Bonn Germany
| | - Johannes Breuer
- Department of Pediatric Cardiology Pediatric Heart Center University Clinic Bonn Bonn Germany
| | - Daniela Wenzel
- Life and Brain Center Institute of Physiology I Medical Faculty University of Bonn Bonn Germany
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Tokajuk A, Karpińska O, Zakrzeska A, Bienias K, Prokopiuk S, Kozłowska H, Kasacka I, Chabielska E, Car H. Dysfunction of aorta is prevented by whey protein concentrate-80 in venous thrombosis-induced rats. J Funct Foods 2016. [DOI: 10.1016/j.jff.2016.09.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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Weston AH, Egner I, Dong Y, Porter EL, Heagerty AM, Edwards G. Stimulated release of a hyperpolarizing factor (ADHF) from mesenteric artery perivascular adipose tissue: involvement of myocyte BKCa channels and adiponectin. Br J Pharmacol 2014; 169:1500-9. [PMID: 23488724 DOI: 10.1111/bph.12157] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 12/31/2012] [Accepted: 03/03/2013] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND AND PURPOSE Perivascular adipose tissue (PVAT) releases adipocyte-derived hyperpolarizing factors (ADHFs) that may partly act by opening myocyte K(+) channels. The present study in rat and mouse mesenteric arteries aimed to identify the myocyte K(+) channel activated by PVAT and to determine whether adiponectin contributed to the hyperpolarizing effects of PVAT. EXPERIMENTAL APPROACH Myocyte membrane potential was recorded from de-endothelialized, non-contracted rat and mouse mesenteric arteries in the presence and absence of PVAT. KEY RESULTS The β3 -adrenoceptor agonist, CL-316,243 (10 μM), generated PVAT-dependent, iberiotoxin-sensitive myocyte hyperpolarizations resulting from BKCa channel opening and which were partially blocked by L-NMMA (100 μM). Adiponectin (5 μg·mL(-1) ) also produced iberiotoxin-sensitive hyperpolarizations in PVAT-denuded arterioles. Activation of myocyte AMP-activated protein kinase (AMPK) using 5 μM A-769662 also induced BKCa -mediated hyperpolarizations. Dorsomorphin abolished hyperpolarizations to CL-316,243, adiponectin and A-769662. In vessels from Adipo(-/-) mice, hyperpolarizations to CL-316,243 were absent whereas those to A-769662 and adiponectin were normal. In rat vessels, adipocyte-dependent hyperpolarizations were blocked by glibenclamide and clotrimazole but those to NS1619 (33 μM) were unaltered. CONCLUSIONS AND IMPLICATIONS Under basal, non-contracted conditions, β3 -adrenoceptor stimulation of PVAT releases an ADHF, which is probably adiponectin. This activates AMPK to open myocyte BKCa channels indirectly and additionally liberates NO, which also contributes to the observed PVAT-dependent myocyte hyperpolarizations. Clotrimazole and glibenclamide each reversed hyperpolarizations to adiponectin and A-769662, suggesting the involvement of myocyte TRPM4 channels in the ADHF-induced myocyte electrical changes mediated via the opening of BKCa channels.
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Affiliation(s)
- A H Weston
- The University of Manchester, Manchester, UK
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7
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Baker JG, Proudman RGW, Hill SJ. Identification of key residues in transmembrane 4 responsible for the secondary, low-affinity conformation of the human β1-adrenoceptor. Mol Pharmacol 2014; 85:811-29. [PMID: 24608857 DOI: 10.1124/mol.114.091587] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The β1-adrenoceptor exists in two agonist conformations/states: 1) a high-affinity state where responses to catecholamines and other agonists (e.g., cimaterol) are potently inhibited by β1-adrenoceptor antagonists, and 2) a low-affinity secondary conformation where agonist responses, particularly CGP12177 [(-)-4-(3-tert-butylamino-2-hydroxypropoxy)-benzimidazol-2-one] are relatively resistant to inhibition by β1-adrenoceptor antagonists. Although both states have been demonstrated in many species (including human), the precise nature of the secondary state is unknown and does not occur in the closely related β2-adrenoceptor. Here, using site-directed mutagenesis and functional measurements of production of a cyclic AMP response element upstream of a secreted placental alkaline phosphatase reporter gene and accumulation of (3)H-cAMP, we examined the pharmacological consequences of swapping transmembrane (TM) regions of the human β1- and β2-adrenoceptors, followed by single point mutations, to determine the key residues involved in the β1-adrenoceptor secondary conformation. We found that TM4 (particularly amino acids L195 and W199) had a major role in the generation of the secondary β1-adrenoceptor conformation. Thus, unlike at the human β1-wild-type adrenoceptor, at β1-TM4 mutant receptors, cimaterol and CGP12177 responses were both potently inhibited by antagonists. CGP12177 acted as a simple partial agonist with similar KB and EC50 values in the β1-TM4 but not β1-wild-type receptors. Furthermore pindolol switched from a biphasic concentration response at human β1-wild-type adrenoceptors to a monophasic concentration response in the β1-TM4 mutant receptors. Mutation of these amino acids to those found in the β2-adrenoceptor (L195Q and W199Y), or mutation of a single residue (W199D) in the human β1-adrenoceptor thus abolished this secondary conformation and created a β1-adrenoceptor with only one high-affinity agonist conformation.
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Affiliation(s)
- Jillian G Baker
- Cell Signalling, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom
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Vasina V, Giannone F, Domenicali M, Latorre R, Berzigotti A, Caraceni P, Zoli M, De Ponti F, Bernardi M. Portal hypertension and liver cirrhosis in rats: effect of the β3-adrenoceptor agonist SR58611A. Br J Pharmacol 2013; 167:1137-47. [PMID: 22708587 DOI: 10.1111/j.1476-5381.2012.02074.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND AND PURPOSE β(3) -Adrenoceptors participate in the regulation of vascular tone in physiological and pathological conditions. We aimed to assess the effect of pharmacological modulation of β(3) -adrenoceptors on portal pressure (PP) and systemic haemodynamics and their expression in the liver and mesenteric vessels of cirrhotic rats. EXPERIMENTAL APPROACH PP, central venous pressure (CVP) and systemic haemodynamics were invasively assessed in control and CCl(4) -treated cirrhotic rats before and during infusion of the selective β(3) -adrenoceptor agonist, SR58611A. Tissue samples were also collected from liver, heart, portal vein and mesenteric artery for immunohistochemistry and molecular biology analysis. The effect of SR58611A on isolated portal vein was assessed. KEY RESULTS At baseline, cirrhotic rats showed portal hypertension, reduced CVP and hyperdynamic circulation. SR58611A induced a significant, dose-dependent decrease in PP in cirrhotic rats, but not in controls. Although both groups manifested a dose-dependent reduction in mean arterial pressure, this effect was associated with decreased cardiac index (CI) and unchanged indicized peripheral vascular resistance (PVRI) in cirrhotic rats and increased CI and decreased PVRI in control animals. Pretreatment with the selective β(3) -adrenoceptor antagonist SR59230 prevented all SR58611A-induced changes in cirrhotic rats. SR58611A concentration-dependently relaxed portal vein in cirrhotic rats to a significantly greater extent than in healthy rats; pretreatment with SR59230A completely prevented SR58611A-induced cirrhotic portal vein relaxation. Finally, β(3) -adrenoceptors were identified in the liver, heart and portal vein of cirrhotic and control animals; their expression was increased in cirrhotic rats. CONCLUSIONS AND IMPLICATIONS β(3) -Adrenoceptors are altered in portal hypertension of experimental cirrhosis and may represent a novel therapeutic target.
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Affiliation(s)
- Valentina Vasina
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
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9
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Baker JG. A full pharmacological analysis of the three turkey β-adrenoceptors and comparison with the human β-adrenoceptors. PLoS One 2010; 5:e15487. [PMID: 21152092 PMCID: PMC2994877 DOI: 10.1371/journal.pone.0015487] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2010] [Accepted: 10/01/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND There are three turkey β-adrenoceptors: the original turkey β-adrenoceptor from erythrocytes (tβtrunc, for which the X-ray crystal structure has recently been determined), tβ3C and tβ4C-receptors. This study examined the similarities and differences between these avian receptors and mammalian receptors with regards to binding characteristics and functional high and low affinity agonist conformations. METHODOLOGY/PRINCIPAL FINDINGS Stable cell lines were constructed with each of the turkey β-adrenoceptors and 3H-CGP12177 whole cell binding, CRE-SPAP production and (3)H-cAMP accumulation assays performed. It was confirmed that the three turkey β-adrenoceptors are distinct from each other in terms of amino acid sequence and binding characteristics. The greatest similarity of any of the turkey β-adrenoceptors to human β-adrenoceptors is between the turkey β3C-receptor and the human β2-adrenoceptor. There are pharmacologically distinct differences between the binding of ligands for the tβtrunc and tβ4C and the human β-adrenoceptors (e.g. with CGP20712A and ICI118551). The tβtrunc and tβ4C-adrenoceptors appear to exist in at least two different agonist conformations in a similar manner to that seen at both the human and rat β1-adrenoceptor and human β3-adrenoceptors. The tβ3C-receptor, similar to the human β2-adrenoceptor, does not, at least so far, appear to exist in more than one agonist conformation. CONCLUSIONS/SIGNIFICANCE There are several similarities, but also several important differences, between the recently crystallised turkey β-adrenoceptor and the human β-adrenoceptors. These findings are important for those the field of drug discovery using the recently structural information from crystallised receptors to aid drug design. Furthermore, comparison of the amino-acid sequence for the turkey and human adrenoceptors may therefore shed more light on the residues involved in the existence of the secondary β-adrenoceptor conformation.
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Affiliation(s)
- Jillian G Baker
- Institute of Cell Signalling, University of Nottingham, Nottingham, United Kingdom.
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10
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Abstract
O exercício aeróbio promove efeitos benéficos na prevenção e tratamento de doenças como hipertensão arterial, aterosclerose, insuficiência venosa e doença arterial periférica. Os receptores β-adrenérgicos estão presentes em várias células. No sistema cardiovascular, promovem inotropismo e cronotropismo positivo cardíaco e relaxamento vascular. Embora os efeitos do exercício tenham sido investigados em receptores cardíacos, estudos focados nos vasos são escassos e controversos. Esta revisão abordará os efeitos do exercício físico sobre os receptores β-adrenérgicos vasculares em modelos animais e humanos e os mecanismos celulares envolvidos na resposta relaxante. Em geral, os estudos mostram resultantes conflitantes, onde observam diminuição, aumento ou nenhum efeito do exercício físico sobre a resposta relaxante. Assim, os efeitos do exercício na sensibilidade β-adrenérgica vascular merecem maior atenção, e os resultados mostram que a área de fisiopatologia vascular é um campo aberto para a descoberta de novos compostos e avanços na prática clínica.
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11
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Dessy C, Balligand JL. Beta3-adrenergic receptors in cardiac and vascular tissues emerging concepts and therapeutic perspectives. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2010; 59:135-63. [PMID: 20933201 DOI: 10.1016/s1054-3589(10)59005-7] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Catecholamines released by the orthosympathetic system play a major role in the short- and long-term regulation of cardiovascular function. Beta1- and beta2-adrenoreceptors (ARs) have classically been considered as mediating most of their effects on cardiac contraction. After their initial cloning and pharmacologic characterization in the late 1980s, beta3-ARs have been mostly thought of as receptors mediating metabolic effects (e.g., lipolysis) in adipocytes. However, definitive evidence for their expression and functional coupling in cardiovascular tissues (including in humans) has recently initiated a re-examination of their implication in the pathophysiology of cardiovascular diseases. Distinctive pharmacodynamic properties of beta3-AR, e.g., their upregulation in disease and resistance to desensitization, suggest that they may be attractive targets for therapeutic intervention. They may substitute efficient vasodilating pathways when beta1/2-ARs are inoperative. In the heart, their contractile effects, which are functionally antipathetic to those of beta1/2-AR, may protect the myocardium against adverse effects of excessive catecholamine stimulation and perhaps mediate additional ancillary effects on key aspects of electrophysiology or remodeling. Longitudinal studies in animals and patients with different stages of heart failure are now needed to identify the optimal therapeutic scheme using specific combinations of agonists or antagonists at all three beta-ARs.
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Affiliation(s)
- Chantal Dessy
- Pole of Pharmacology and Therapeutics, Institute of Experimental and Clinical Research, Université catholique de Louvain, Brussels, Belgium
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12
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Carteolol, a non-conventional partial agonist of β1-adrenoceptors, relaxes phenylephrine-constricted rat aorta through antagonism at α1-adrenoceptors. Eur J Pharmacol 2008; 590:269-75. [DOI: 10.1016/j.ejphar.2008.05.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2008] [Revised: 04/24/2008] [Accepted: 05/19/2008] [Indexed: 11/21/2022]
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Kaumann AJ, Molenaar P. The low-affinity site of the β1-adrenoceptor and its relevance to cardiovascular pharmacology. Pharmacol Ther 2008; 118:303-36. [DOI: 10.1016/j.pharmthera.2008.03.009] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Accepted: 03/20/2008] [Indexed: 10/22/2022]
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Al Zubair K, Bexis S, Docherty JR. Relaxations to beta-adrenoceptor subtype selective agonists in wild-type and NOS-3-KO mouse mesenteric arteries. Eur J Pharmacol 2008; 587:216-23. [PMID: 18455721 DOI: 10.1016/j.ejphar.2008.03.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2007] [Revised: 02/27/2008] [Accepted: 03/10/2008] [Indexed: 12/16/2022]
Abstract
We have investigated the role of nitric oxide (NO) in relaxations to beta-adrenoceptor agonists in mesenteric artery from wild-type (WT) and NO synthase-3 knockout (NOS-3-KO) mice. Isoprenaline, formoterol and BRL 37344 ((R(),R())-(+/-)-4-[2-[(2-(3-chlorophenyl)-2-hydroxyethyl)amino]propyl]phenoxyacetic acid) were chosen as non-selective and beta(2)- and beta(3)-adrenoceptor agonists, respectively. Atenolol, ICI 118,551 ((+/-)-1-[2,3-(dihydro-7-methyl-1H-inden-4-yl)oxy]-3-[(1-methylethyl)amino]-2-butanol hydrochloride) and SR59230A (1-(2-ethylphenoxy)-3-[[(1S)-1,2,3,4-tetrahydro-1-naphthalenyl]amino]-(2S)-2-propanol hydrochloride) were chosen as selective beta(1)-, beta(2)- and beta(3)-adrenoceptor antagonists, respectively. Experiments employing isoprenaline were carried out in the presence of prazosin (0.1 microM). Isoprenaline produced relaxations with a potency of 5.68+/-0.36 (-log M, n=6) in WT mice. Relaxations to isoprenaline were blocked by atenolol (10 microM) and were absent in vessels from NOS-3-KO animals. Formoterol produced relaxations with two components. ICI 118,551 (1 microM) abolished relaxations to low concentrations of formoterol (0.1-10 microM), but failed to affect relaxations to formoterol (100 microM). In NOS-3-KO mice only the highest concentration of formoterol (100 microM) produced relaxations: the relaxation was resistant to all of the beta-adrenoceptor antagonists employed. BRL 37344 (5.75+/-0.28, n=9) was approximately equipotent with isoprenaline but produced a smaller degree of relaxation, in WT mice. SR59230A (1 microM) abolished relaxations to BRL 37344 in WT mice. In NOS-3-KO mice, BRL 37344 produced concentration-dependent relaxations which were abolished by SR59230A. It is concluded that the predominant beta-adrenoceptor mediating relaxations in mouse mesenteric artery is beta(1), and relaxations involve NOS-3. In addition, beta(3)-adrenoceptors mediate smaller relaxations at least partly independent of NOS-3, and beta(2)-adrenoceptors may mediate smaller relaxations dependent on NOS-3.
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Affiliation(s)
- Khaled Al Zubair
- Department of Physiology, Royal College of Surgeons in Ireland, 123 St. Stephens's Green, Dublin 2, Ireland
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15
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Abstract
Most modern theories about stress recognize that although stress is not a disease, it may be the trigger for the majority of diseases when allostatic overload has been generated. During stress, the glucocorticoids and catecholamines play a key role in the regulation of physiological parameters and homeostasis during stress. In the heart, positive chronotropic, inotropic, and lusitropic responses to catecholamines are mediated by various subtypes of adrenergic receptors (beta-ARs), mainly beta1- and beta2-adrenergic receptors. beta-ARs also control cardiomyocyte growth and death, thus contributing to cardiac remodelling. The structural basis of each beta-AR subtype, as well as their signalling pathways, and adaptive responses to stress are discussed. The participation of beta3- and putative beta4-ARs in the control of cardiac function is also discussed, with emphasis on low affinity beta-AR isoforms and the role they play in the response to the catecholamines under stress. The changes in beta-AR signalling under pathogenic conditions as well as under stress are reviewed.
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Affiliation(s)
- Iraídes N Santos
- Institute of Biology, State University of Campinas (UNICAMP), Department of Physiology and Biophysics, Campinas, SP, Brazil
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16
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Bieger D, Parai K, Ford CA, Tabrizchi R. beta-adrenoceptor mediated responses in rat pulmonary artery: putative role of TASK-1 related K channels. Naunyn Schmiedebergs Arch Pharmacol 2006; 373:186-96. [PMID: 16736155 DOI: 10.1007/s00210-006-0060-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2005] [Accepted: 03/06/2006] [Indexed: 11/29/2022]
Abstract
The effect of isoprenaline on tone, cyclic adenosine 3':5' monophosphate (cAMP), and smooth muscle membrane potential (E ( m )) were assessed in rat isolated pulmonary arteries. N(omega)-nitro-L-arginine methyl ester (10.0 microM) or removal of endothelium partially inhibited relaxant responses to isoprenaline, but glibenclamide (10.0 microM) and indomethacin (10.0 microM) did not. While Rp-8-Br-cAMP (30.0 microM), tetraethylammonium (0.3 & 1.0 mM), 4-aminopyridine (100 microM), anandamide (10.0 microM), charybdotoxin (0.1 microM), ouabain (100 microM), and barium chloride (100 microM), incompletely blocked relaxation to isoprenaline, cyclopiazonic acid (1.0 microM), apamin (3.0 microM) and zinc acetate (300 microM) were without effect. Increasing extracellular K(+) ([K(+)](e)) inhibited relaxant responses to isoprenaline, completely abolishing the response at 30 mM [K+](e). Vasorelaxant effects of isoprenaline were significantly attenuated in buffer pH 6.4, and concomitant presence of Rp-8-Br-cAMP (30.0 microM) in pH 6.4 produced significant additive inhibition when compared to pH 6.4 without Rp-8-Br-cAMP. Isoprenaline increased cAMP turnover (1.55+/-0.24 fold; mean +/- SEM), which was inhibited by propranolol (1.0 microM). Resting E ( m ) of smooth muscle cells was -63.0+/-0.50 mV, and isoprenaline (1.0 microM) produced hyperpolarisation (-73.3+/-0.80 mV). While glibenclamide failed to affect isoprenaline-induced hyperpolarisation, ICI 118,551 (1.0 microM), anandamide or buffer pH 6.4 prevented it, and barium chloride and oubain combined caused partial inhibition. Isoprenaline-mediated relaxation seems to arise from several processes, including the generation of nitric oxide, the cAMP-cascade and, more importantly, a hyperpolarisation that is not due to activation of ATP-sensitive K channels but possibly of two-pore domain K channels of the TASK family.
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Affiliation(s)
- Detlef Bieger
- Division of Basic Medical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
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17
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Zakrzeska A, Schlicker E, Kwolek G, Kozłowska H, Malinowska B. Positive inotropic and lusitropic effects mediated via the low-affinity state of beta1-adrenoceptors in pithed rats. Br J Pharmacol 2006; 146:760-8. [PMID: 16151438 PMCID: PMC1751196 DOI: 10.1038/sj.bjp.0706382] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1 Activation by CGP 12177 and cyanopindolol of the human and rat low-affinity state of beta(1)-adrenoceptors increases frequency and contractile force and hastens relaxation in isolated cardiac tissues, and probably relaxes isolated vessels. In order to identify the positive inotropic, positive lusitropic and vasodilator effects of both agonists also in vivo, we have determined their effects on the left ventricular systolic pressure (LVSP), the rate of intraventricular pressure rise (+dP dt(-1)(max)) and decline (-dP dt(-1)(max)), the diastolic blood pressure (DBP) and the mesenteric blood flow (MBF) in pithed and vagotomized rats. 2 CGP 12177 (0.1-100 nmol kg(-1)) and cyanopindolol (1-1000 nmol kg(-1)) dose-dependently enhanced all cardiac parameters. The nonselective beta-adrenoceptor antagonist bupranolol 10 micromol kg(-1) diminished the CGP 12177 (100 nmol kg(-1))-stimulated increases in LVSP from 26.3+/-8.2 to 13.1+/-1.8 mmHg (P<0.05), +dP dt(-1)(max) from 5287+/-290 to 2439+/-296 mmHg s(-1) (P<0.001) and -dP dt(-1)(max) from -3836+/-301 to -2187+/-443 mmHg s(-1) (P<0.05), respectively. The beta(1)-adrenoceptor antagonist CGP 20712A 10 micromol kg(-1) (known to block the low-affinity state of beta(1)-adrenoceptors at high doses) inhibited increases in +/-dP dt(-1)(max) elicited by the highest dose of CGP 12177. 3 The highest doses of CGP 12177 and cyanopindolol increased DBP by about 10 mmHg and MBF by 1.4+/-0.3 and 0.6+/-0.3 ml min(-1), respectively. The vascular effects of CGP 12177 were not affected by bupranolol and CGP 20712A. 4 In conclusion, activation of the low-affinity state of beta(1)-adrenoceptors by CGP 12177 and cyanopindolol in pithed rats causes a positive inotropic and lusitropic effect. By contrast, the vascular effects of CGP 12177 and cyanopindolol are not mediated by these receptors and have only marginal influence under in vivo conditions.
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Affiliation(s)
- Agnieszka Zakrzeska
- Zakład Fizjologii Doświadczalnej, Akademia Medyczna w Białymstoku, ul. Mickiewicza 2A, 15-089 Białystok, Poland
| | - Eberhard Schlicker
- Institut für Pharmakologie und Toxikologie, Universität Bonn, Reuterstrasse 2b, 53113 Bonn, Germany
| | - Grzegorz Kwolek
- Zakład Fizjologii Doświadczalnej, Akademia Medyczna w Białymstoku, ul. Mickiewicza 2A, 15-089 Białystok, Poland
| | - Hanna Kozłowska
- Zakład Fizjologii Doświadczalnej, Akademia Medyczna w Białymstoku, ul. Mickiewicza 2A, 15-089 Białystok, Poland
| | - Barbara Malinowska
- Zakład Fizjologii Doświadczalnej, Akademia Medyczna w Białymstoku, ul. Mickiewicza 2A, 15-089 Białystok, Poland
- Author for correspondence:
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18
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Briones AM, Daly CJ, Jimenez-Altayo F, Martinez-Revelles S, Gonzalez JM, McGrath JC, Vila E. Direct demonstration of beta1- and evidence against beta2- and beta3-adrenoceptors, in smooth muscle cells of rat small mesenteric arteries. Br J Pharmacol 2005; 146:679-91. [PMID: 16113691 PMCID: PMC1751207 DOI: 10.1038/sj.bjp.0706369] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2005] [Revised: 06/23/2005] [Accepted: 07/18/2005] [Indexed: 11/08/2022] Open
Abstract
1 Recent evidence supports additional subtypes of vasodilator beta-adrenoceptor (beta-AR) besides the 'classical' beta(2). The aim of this study was to investigate the distribution of beta-ARs in the wall of rat mesenteric resistance artery (MRA), to establish the relative roles of beta-ARs in smooth muscle and other cell types in mediating vasodilatation and to analyse this in relation to the functional pharmacology. 2 We first examined the vasodilator beta-AR subtype using 'subtype-selective' agonists against the, commonly employed, phenylephrine-induced tone. Concentration-related relaxation was produced by isoprenaline (pEC(50): 7.70+/-0.1) (beta(1) and beta(2)). Salbutamol (beta(2)), BRL 37344 (beta(3)) and CGP 12177 (atypical beta) caused relaxation but were 144, 100 and 263 times less potent than isoprenaline; the 'beta(3)-adrenoceptor agonist' CL 316243 was ineffective. 3 In arteries precontracted with 5-HT or U 46619, isoprenaline produced concentration-related relaxation but salbutamol, BRL 37344, CGP 12177 and CL 316243 did not. SR 59230A, CGP 12177 and BRL 37344 caused a parallel rightward shift in the concentration-response curve to phenylephrine indicating competitive alpha(1)-AR antagonism, explaining the false-positive 'vasodilator' action against phenylephrine-induced tone. Endothelial denudation but not L-NAME slightly attenuated isoprenaline-mediated vasodilatation in phenylephrine and U 46619 precontracted MRA. 4 The beta-AR fluorescent ligand BODIPY TMR-CGP 12177 behaved as an irreversible beta(1)-AR antagonist in MRA and bound to the surface and inside vascular smooth muscle cells in intact vascular wall. Beta-ARs in smooth muscle cells were observed in a perinuclear location, consistent with the location of Golgi and endoplasmic reticulum. 5 Binding of BODIPY TMR-CGP 12177 was inhibited by BAAM (1 microM) in all three vascular tunics, confirming the presence of beta-ARs in adventitia, media and intima. Binding in adventitia was observed in both neuronal and non-neuronal cell types. Lack of co-localisation with a fluorescent ligand for alpha-ARs confirms the selectivity of BODIPY TMR-CGP 12177 for beta-ARs over alpha-ARs. 6 Our results support the presence of functional vasodilator beta(1)-ARs and show that they are mainly located in smooth muscle cells. Furthermore, we have demonstrated, for the first time, the usefulness of BODIPY TMR-CGP 12177 for identifying beta-AR distribution in the 'living' vascular wall.
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MESH Headings
- Adrenergic beta-Agonists/pharmacology
- Adrenergic beta-Antagonists/pharmacology
- Animals
- Boron Compounds/pharmacology
- Cells, Cultured
- Dioxoles/pharmacology
- Ethanolamines/pharmacology
- Imidazoles/pharmacology
- Mesenteric Arteries/cytology
- Mesenteric Arteries/drug effects
- Mesenteric Arteries/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/metabolism
- Phenylephrine/pharmacology
- Propanolamines/pharmacology
- Rats
- Rats, Inbred WKY
- Receptors, Adrenergic, beta/metabolism
- Receptors, Adrenergic, beta/physiology
- Vasodilation/physiology
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Affiliation(s)
- Ana M Briones
- Departament de Farmacologia, de Terapeutica i de Toxicologia, Institut de Neurociències, Facultat de Medicina, Universitat Autònoma de Barcelona, 08193 Bellatera, Spain
| | - Craig J Daly
- Faculty of Biomedical and Life Sciences, Division of Neuroscience and Biomedical Systems, University of Glasgow, Wolfson Building (Office 448), West Medical Building (Lab 440), University Avenue, Glasgow G12 8QQ
| | - Francesc Jimenez-Altayo
- Departament de Farmacologia, de Terapeutica i de Toxicologia, Institut de Neurociències, Facultat de Medicina, Universitat Autònoma de Barcelona, 08193 Bellatera, Spain
| | - Sonia Martinez-Revelles
- Departament de Farmacologia, de Terapeutica i de Toxicologia, Institut de Neurociències, Facultat de Medicina, Universitat Autònoma de Barcelona, 08193 Bellatera, Spain
| | - Jose M Gonzalez
- Faculty of Biomedical and Life Sciences, Division of Neuroscience and Biomedical Systems, University of Glasgow, Wolfson Building (Office 448), West Medical Building (Lab 440), University Avenue, Glasgow G12 8QQ
| | - John C McGrath
- Faculty of Biomedical and Life Sciences, Division of Neuroscience and Biomedical Systems, University of Glasgow, Wolfson Building (Office 448), West Medical Building (Lab 440), University Avenue, Glasgow G12 8QQ
| | - Elisabet Vila
- Departament de Farmacologia, de Terapeutica i de Toxicologia, Institut de Neurociències, Facultat de Medicina, Universitat Autònoma de Barcelona, 08193 Bellatera, Spain
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19
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Pourageaud F, Leblais V, Bellance N, Marthan R, Muller B. Role of β2-adrenoceptors (ß-AR), but not ß1-, β3-AR and endothelial nitric oxide, in β-AR-mediated relaxation of rat intrapulmonary artery. Naunyn Schmiedebergs Arch Pharmacol 2005; 372:14-23. [PMID: 16133491 DOI: 10.1007/s00210-005-1082-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2005] [Accepted: 07/01/2005] [Indexed: 10/25/2022]
Abstract
The aim of this study was to analyze beta-adrenoceptor (beta-AR)-mediated relaxation in rat intralobar pulmonary artery. The relaxant responses of beta-AR agonists were characterized using beta-AR antagonists in prostaglandin F2alpha (PGF2alpha)-precontracted arteries. The role of nitric oxide (NO) and endothelium in beta-AR-mediated relaxation was also investigated. Isoprenaline (a non-selective beta-AR agonist) and salbutamol (a selective beta2-AR agonist) induced vasorelaxation. ICI 118551 (a selective beta2-AR antagonist) antagonized the effect of both isoprenaline and salbutamol (pA2 values of 9.57 and 9.51 respectively). In contrast, atenolol (1 microM) and CGP 20712A (0.1 microM), two beta1-AR antagonists, did not modify the relaxing effect of isoprenaline. The response to isoprenaline obtained in the presence of nadolol (10 microM, a beta1/beta2-AR antagonist) was not further inhibited by SR 59230A (1 microM, a selective beta3-AR antagonist). The non-beta1/beta2-AR agonists studied (BRL 37344, SR 58611A, and CGP 12177A) did not elicit vasorelaxation. Relaxation to isoprenaline and salbutamol was unaffected by L-N(G)-nitro-arginine methyl ester (100 microM, an inhibitor of NO synthase) or after endothelium removal. These results demonstrate the role of beta2-AR in mediating relaxation in rat intralobar pulmonary artery precontracted with PGF2alpha. They indicate that beta2-AR-mediated relaxation in this artery is NO- and endothelium-independent. Furthermore, they do not provide evidence of a relaxant role of either beta1- or beta3-AR in PGF2alpha-precontracted rat intrapulmonary artery.
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MESH Headings
- Adrenergic beta-Agonists/pharmacology
- Adrenergic beta-Antagonists/pharmacology
- Albuterol/pharmacology
- Animals
- Atenolol/pharmacology
- Dose-Response Relationship, Drug
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/enzymology
- In Vitro Techniques
- Isoproterenol/pharmacology
- Male
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- NG-Nitroarginine Methyl Ester/pharmacology
- Nitric Oxide/metabolism
- Nitric Oxide Synthase/antagonists & inhibitors
- Propanolamines/pharmacology
- Pulmonary Artery/drug effects
- Pulmonary Artery/metabolism
- Rats
- Rats, Wistar
- Receptors, Adrenergic, beta-1/analysis
- Receptors, Adrenergic, beta-1/drug effects
- Receptors, Adrenergic, beta-2/analysis
- Receptors, Adrenergic, beta-2/drug effects
- Receptors, Adrenergic, beta-2/metabolism
- Receptors, Adrenergic, beta-3/analysis
- Receptors, Adrenergic, beta-3/drug effects
- Vasodilation/drug effects
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Affiliation(s)
- Fabrice Pourageaud
- Laboratoire de Pharmacologie de la Faculté de Pharmacie, INSERM EMI-0356, Université Victor Segalen Bordeaux 2, Casier 83, 146 rue Léo Saignat, 33076, Bordeaux cedex, France.
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20
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Kozłowska H, Schlicker E, Kozłowski M, Siedlecka U, Laudański J, Malinowska B. Ligands at β2-, β3-, and the Low-Affinity State of β1-Adrenoceptors Block the α1-Adrenoceptor-Mediated Constriction in Human Pulmonary and Rat Mesenteric Arteries. J Cardiovasc Pharmacol 2005; 46:76-82. [PMID: 15965358 DOI: 10.1097/01.fjc.0000162775.23139.3e] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We examined whether the beta2-adrenoceptor agonists fenoterol and salbutamol, the beta3-adrenoceptor agonists CL 316243 and ZD 2079, and the agonists of the low-affinity state of beta-adrenoceptors, cyanopindolol and CGP 12177 block alpha1-adrenoceptors in that concentration range in which they relax the human pulmonary and rat mesenteric arteries preconstricted with phenylephrine 10 microM and 1 microM, respectively. For quantification of vasodilatation pEC25 values and for the antagonism toward alpha1-adrenoceptors, pA2 values were determined. We found that in the rat mesenteric artery, (1) the pEC25 values of the beta-adrenoceptor ligands resemble their respective pA2 values (difference < or = 0.9 log units), and (2) the order of potencies is the same for both parameters, ie, cyanopindolol approximately fenoterol > CGP 12177 > salbutamol > ZD 2079 > CL 316243. In the human pulmonary artery, (1) the pEC25 values are slightly lower (by 0.6-1.3 log units) than their respective pA2 values, and (2) the rank order of potencies is the same for both parameters. In conclusion, the present study suggests that ligands of beta2-adrenoceptors and of non-beta1-non-beta2-adrenoceptors relax rat and human vessels preconstricted with phenylephrine or norepinephrine mainly through their alpha1-adrenolytic effects. Hence, for the investigation of the role of beta-adrenoceptors in vessels, the constrictor agent should be chosen with great caution.
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Affiliation(s)
- Hanna Kozłowska
- Department of Experimental Physiology, Medical University of Białystok, Białystok, Poland
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21
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Arch JRS. Do low-affinity states of beta-adrenoceptors have roles in physiology and medicine? Br J Pharmacol 2005; 143:517-8. [PMID: 15514247 PMCID: PMC1575436 DOI: 10.1038/sj.bjp.0705991] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The pharmacology once ascribed to the 'beta4-adrenoceptor' is now believed to be that of a low-affinity state of the beta1-adrenoceptor. The beta2-adrenoceptor may also have a low-affinity state or site, while the beta3-adrenoceptor--the original low-affinity beta-adrenoceptor--can display more than one pharmacology. In this issue, Mallem et al. show that CGP-12177 relaxes thoracic aorta rings from normal rats by stimulating vascular smooth muscle low-affinity beta1-adrenoceptors, apparently linked in part to Gi protein. By contrast, in rings from hypertensive rats, CGP-12177 acts mainly via endothelial beta3-adrenoceptors. This work raises the possibility that low-affinity states of beta-adrenoceptors have physiological roles, and suggests that they might be drug targets.
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MESH Headings
- Aorta, Thoracic/drug effects
- GTP-Binding Protein alpha Subunits, Gi-Go/drug effects
- GTP-Binding Protein alpha Subunits, Gi-Go/physiology
- Humans
- Muscle Relaxation/drug effects
- Muscle, Smooth, Vascular/drug effects
- Propanolamines/pharmacology
- Receptors, Adrenergic, beta/drug effects
- Receptors, Adrenergic, beta/physiology
- Receptors, Adrenergic, beta-3/drug effects
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Affiliation(s)
- Jonathan R S Arch
- Clore Laboratory for Life Sciences, University of Buckingham, Buckingham, Bucks MK18 1EG.
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22
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Santos IN, Sumitame M, Caceres VM, Moreira MF, Krieger MH, Spadari-Bratfisch RC. Evidence for two atypical conformations of beta-adrenoceptors and their interaction with Gi proteins. Eur J Pharmacol 2005; 513:109-18. [PMID: 15878715 DOI: 10.1016/j.ejphar.2005.03.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2005] [Accepted: 03/02/2005] [Indexed: 11/25/2022]
Abstract
In this study, we investigated whether the responses of right atria from sinoaortic denervated rats to CGP12177 (4(3-t-butylamino-2-hydroxypropoxy benzidimidazole-2 one, hydrochloride)), isoprenaline and norepinephrine desensitized in parallel and whether CGP12177 interacted with distinct conformations of beta-adrenoceptors. Right atria from rats 48 h after sinoaortic denervation were subsensitive to isoprenaline, norepinephrine and CGP12177. One week after sinoaortic denervation, the sensitivity to CGP12177 had recovered whereas the responses to isoprenaline and norepinephrine were still subsensitive, suggesting that the binding sites for these molecules showed independent behavior. In atria from 48 h sinoaortic-denervated rats, propranolol or 3 microM CGP20712A (2-hydroxy-5(2-((2-hydroxy-3-(4-((methyl-4-trifluormethyl)1H imidazole-2-yl)-phenoxypropyl) amino) ethoxy)-benzamide monomethane sulphonate)) blocked the responses to 10 nM-1 microM CGP12177 and steepened the curves. The concentration-response curves to CGP12177 in the presence of ICI118,551 (erythro-DL-1(-methylindan-4-yloxy)-3-isopropylamino-butan-2-ol) were biphasic, suggesting that CGP12177 interacted with at least two conformations of beta-adrenoceptors that showed negative cooperativism, one acting through beta(2)-adrenoceptor-Gi and the other via beta(1)-adrenoceptor-Gs. This hypothesis was confirmed in right atria from sinoaortic-denervated rats treated with pertussis toxin.
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MESH Headings
- Adrenergic alpha-Agonists/pharmacology
- Adrenergic beta-Agonists/pharmacology
- Adrenergic beta-Antagonists/pharmacology
- Animals
- Dose-Response Relationship, Drug
- GTP-Binding Protein alpha Subunits, Gi-Go/metabolism
- Heart/drug effects
- Heart/physiology
- Heart Atria/drug effects
- Heart Atria/innervation
- Imidazoles/pharmacology
- In Vitro Techniques
- Isoproterenol/pharmacology
- Male
- Myocardial Contraction/drug effects
- Norepinephrine/pharmacology
- Pertussis Toxin/pharmacology
- Propanolamines/pharmacology
- Protein Binding
- Protein Conformation
- Rats
- Rats, Wistar
- Receptors, Adrenergic, beta/chemistry
- Receptors, Adrenergic, beta/metabolism
- Receptors, Adrenergic, beta-1/chemistry
- Receptors, Adrenergic, beta-1/metabolism
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Affiliation(s)
- Iraídes N Santos
- Department of Physiology and Biophysics, Institute of Biology, State University of Campinas (UNICAMP), Campinas, SP, Brazil
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Abstract
Antagonist affinity measurements have traditionally been considered important in defining the receptor or receptor subtypes present within cells or tissues. Any change in this value has normally been taken as evidence for the presence of a second receptor. However, highly efficacious ligands induce a time and phosphorylation-dependent change in the beta2-adrenoceptor resulting in 10-fold lower affinity for antagonists. Also the beta1-adrenoceptor is now considered to exist in two different active conformations which are distinguished by their pharmacological properties. In this study, the site of action of a range of beta-agonists and beta-antagonists was determined using the human beta1-adrenoceptor stably expressed in Chinese hamster ovary cells with cyclic AMP response element reporter genes. Adrenaline and noradrenaline were confirmed as having agonist actions via the catecholamine site, whereas all antagonists had higher affinity for the catecholamine rather than secondary site. However, the rank order of affinity for the two sites was different suggesting that they are indeed separate entities. The measurements of antagonist affinity at the catecholamine site, however, were found to depend upon the agonist present. For example, xamoterol, cimaterol, terbutaline, and formoterol agonist responses were more readily antagonized by CGP 20712A[2-hydroxy-5-(2-[{hydroxy-3-(4-[1-methyl-4-trifluoromethyl-2-imidazolyl]phenoxy)propyl}amino]ethoxy)benzamide] than the catecholamine responses themselves. This, however, was not related to agonist efficacy as has previously been reported for the human beta2-adrenoceptor. Therefore, it may be that some agonists (e.g., cimaterol) purely activate the catecholamine site and others purely activate the secondary site (e.g., CGP 12177 [(-)-4-(3-tert-butylamino-2-hydroxypropoxy)-benzimidazol-2-one]), whereas the others (e.g., catecholamines) activate both sites to differing degrees.
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Affiliation(s)
- Jillian G Baker
- Institute of Cell Signaling, Queen's Medical Centre, Nottingham, UK.
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24
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Brahmadevara N, Shaw AM, MacDonald A. ALpha1-adrenoceptor antagonist properties of CGP 12177A and other beta-adrenoceptor ligands: evidence against beta(3)- or atypical beta-adrenoceptors in rat aorta. Br J Pharmacol 2005; 142:781-7. [PMID: 15205310 PMCID: PMC1575050 DOI: 10.1038/sj.bjp.0705840] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1. The alpha(1)-adrenoceptor antagonist properties of the beta-adrenoceptor nonconventional partial agonist, CGP 12177A, was investigated in functional assays in rat aorta and in radioligand binding assays in rat cerebral cortical membranes. In addition, binding affinities of other beta-adrenoceptor ligands were measured to investigate any correlation between alpha(1)-adrenoceptor affinity and relaxant potency in phenylephrine-constricted rings. 2. In functional studies, CGP 12177A produced parallel rightward shifts of the phenylephrine CRC with no reduction in the maximum responses. Schild regression analysis gave a straight line with a slope of 0.95 (95% CL: 0.87-1.04), suggesting reversible competitive antagonism, and gave a pK(B) value of 5.26. In contrast, CGP 12177A (<or=300 microm) had no effect on contraction induced by the thromboxane-mimetic, U46619. 3. In binding studies, CGP 12177A competed monophasically with [(3)H]prazosin binding (Hill slope, 0.95, 95% CL: 0.76-1.13), giving a pK(i) value of 5.48, in good agreement with the pK(B) from functional studies. 4. Competition experiments with various other beta-adrenoceptor ligands showed that they all displaced [(3)H]prazosin in a manner consistent with one-site competition. pK(i) values were as follows: SR 59230A, 6.25; cyanopindolol, 6.33; bupranolol, 6.35; alprenolol, 5.90; propranolol, 5.80; BRL 37344, 5.50; ICI 118551, 5.55; CGP 20712A, 5.26. The pK(i) values correlated well with the pEC(50) values for relaxation of phenylephrine-constricted rat aorta obtained previously (r(2)=0.984, P<0.0001). 5. In conclusion, relaxant effects of CGP 12177A and other beta-adrenoceptor ligands in phenylephrine-constricted rat aorta can be attributed to alpha(1)-adrenoceptor blockade and are unrelated to effects at beta(3)-adrenoceptors or atypical beta-adrenoceptors.
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MESH Headings
- 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid/pharmacology
- Adrenergic alpha-1 Receptor Antagonists
- Adrenergic beta-Antagonists/administration & dosage
- Adrenergic beta-Antagonists/pharmacokinetics
- Alprenolol/pharmacology
- Animals
- Aorta, Thoracic/drug effects
- Aorta, Thoracic/pathology
- Aorta, Thoracic/physiology
- Binding Sites/drug effects
- Bupranolol/pharmacology
- Cell Membrane/drug effects
- Cell Membrane/metabolism
- Cerebral Cortex/drug effects
- Cerebral Cortex/metabolism
- Cerebral Cortex/pathology
- Dose-Response Relationship, Drug
- Ethanolamines/pharmacology
- Imidazoles/pharmacology
- Male
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/physiology
- Phenylephrine/administration & dosage
- Phenylephrine/antagonists & inhibitors
- Phenylephrine/pharmacokinetics
- Pindolol/analogs & derivatives
- Pindolol/pharmacology
- Prazosin/administration & dosage
- Prazosin/pharmacokinetics
- Propanolamines/administration & dosage
- Propanolamines/pharmacokinetics
- Propanolamines/pharmacology
- Propranolol/pharmacology
- Radioligand Assay/methods
- Rats
- Rats, Wistar
- Receptors, Adrenergic, alpha-1/physiology
- Receptors, Adrenergic, beta-3/drug effects
- Receptors, Adrenergic, beta-3/physiology
- Tritium
- United Kingdom
- Vasoconstriction/drug effects
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Affiliation(s)
- Nataraj Brahmadevara
- Department of Biological and Biomedical Sciences, School of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, U.K
| | - Angus M Shaw
- Department of Biological and Biomedical Sciences, School of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, U.K
| | - Allan MacDonald
- Department of Biological and Biomedical Sciences, School of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, U.K
- Author for correspondence:
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25
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Leblais V, Pourageaud F, Ivorra MD, Guibert C, Marthan R, Muller B. Role of alpha-adrenergic receptors in the effect of the beta-adrenergic receptor ligands, CGP 12177, bupranolol, and SR 59230A, on the contraction of rat intrapulmonary artery. J Pharmacol Exp Ther 2004; 309:137-45. [PMID: 14718590 DOI: 10.1124/jpet.103.061192] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study investigates the effect of the aryloxypropanolamines 4-[3-[(1,1-dimethylethyl)amino]-2-hydroxypropoxy]-1,3-dihydro-2H-benzimidazol-2-one (CGP 12177), bupranolol, and 3-(2-ethylphenoxy)-1[(1S)-1,2,3,4-tetrahydronaphth-1-ylamino]-(2S)-2-propanol oxalate (SR 59230A) [commonly used as beta(3)- and/or atypical beta-adrenergic receptors (beta-AR) ligands] on the contractile function of rat intralobar pulmonary artery. Affinities of beta-AR ligands for alpha(1)-adrenergic receptors (alpha(1)-AR) were also evaluated using [(3)H]prazosin binding competition experiments performed in rat cortical membranes. In intralobar pulmonary artery, CGP 12177 did not modify the basal tone, but antagonized the contraction induced by the alpha(1)-AR agonist phenylephrine (PHE). In arteries precontracted with PHE, CGP 12177 elicited relaxation, whereas in those precontracted with prostaglandin F(2alpha) (PGF(2alpha)), it further enhanced contraction. CGP 12177 induced an increase in intracellular calcium concentration in pressurized arteries loaded with Fura PE-3 and precontracted with PGF(2alpha). In PGF(2alpha) precontracted arteries, phentolamine (an alpha-AR antagonist) and phenoxybenzamine (an irreversible alpha-AR antagonist) antagonized the contractile responses to PHE and CGP 12177. Both responses were also decreased by bupranolol and SR 59230A. Specific [(3)H]prazosin binding was displaced by CGP 12177, bupranolol, and SR 59230A with pK(i) values of 5.2, 5.7, and 6.6, respectively. In contrast, (+/-)-(R*,R*)-[4-[2-[[2-(3-chlorophenyl)-2-hydroxyethyl]amino]propyl]phenoxy]acetic acid sodium (BRL 37344) and disodium 5-[(2R)-2-([(2R)-2-(3-chlorophenyl)-2-hydroxyethyl]amino)propyl]-1,3-benzodioxole-2,2-dicarboxylate (CL 316243) (nonaryloxypropanolamines beta(3)-AR agonists) displayed very low affinity for [(3)H]prazosin binding sites (pK(i) values below 4). These data suggest that CGP 12177 exhibits partial agonist properties for alpha(1)-AR in rat pulmonary artery. They also show that bupranolol and SR 59230A exert an alpha(1)-AR antagonist effect. As a consequence, these aryloxypropanolamine compounds should be used with caution when investigating the role of beta(3)- and atypical beta-AR in the regulation of vascular tone.
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Affiliation(s)
- Véronique Leblais
- Laboratoire de Pharmacologie de la Faculté de Pharmacie, INSERM EMI-0356, Université Victor Segalen Bordeaux 2-Casier 83, 146 rue Léo Saignat, 33076 Bordeaux cedex, France.
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Affiliation(s)
- Peter Molenaar
- The National Heart Foundation, Chermside, Queensland 4032, Australia.
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