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Carrington EF, Desautels M, Naylor JM. β-Adrenergic stimulated lipolysis in pony adipocytes is exclusively via a β2-subtype and is not affected by lactation. Comp Biochem Physiol A Mol Integr Physiol 2003; 136:311-20. [PMID: 14511750 DOI: 10.1016/s1095-6433(03)00157-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Catecholamines are important lipolytic agents in horses and ponies but the nature of the adrenergic receptor subtype distribution in their adipocytes is uncertain. A first objective was to identify the beta-adrenergic receptor subtype(s) present in adipocytes from horses and ponies. A second objective was to evaluate if the lipolytic responsiveness of isolated adipocytes to beta-adrenergic agonists is altered during lactation, a condition known to affect markedly maternal fat metabolism. Isoproterenol and salbutamol elicited strong lipolytic responses in adipocytes isolated from horse and pony subcutaneous adipose tissue. There were weak lipolytic responses to norepinephrine, dobutamine and BRL37344. The weak lipolytic response to NE compared to isoproterenol or salbutamol suggests an antilipolytic action from alpha2-adrenergic receptors. The relative order of potency for the beta-adrenergic agonists was isoproterenol>/=salbutamol>>dobutamine=BRL37344. There was expression of beta2-adrenergic receptor mRNA in pony and horse adipose tissues, as estimated by relative RT-PCR, but no expression of mRNAs for beta1- or beta3-adrenergic receptors. Early lactation did not alter the lipolytic responses to beta-adrenergic agonists, nor the expression of beta2-adrenergic receptor mRNA. Thus, these results indicate a dominant if not exclusive presence of beta2-adrenergic receptors in pony and horse adipocytes that is not affected by lactation.
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Affiliation(s)
- E F Carrington
- University of Saskatchewan, Western College of Veterinary Medicine, Department of Large Animal Clinical Sciences, 52 Campus Drive, 107 Wiggins Road, S7N5B4, Saskatoon, SK, Canada.
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102
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Nickerson JG, Dugan SG, Drouin G, Perry SF, Moon TW. Activity of the unique beta-adrenergic Na+/H+ exchanger in trout erythrocytes is controlled by a novel beta3-AR subtype. Am J Physiol Regul Integr Comp Physiol 2003; 285:R526-35. [PMID: 12775554 DOI: 10.1152/ajpregu.00146.2003] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
beta-Adrenoceptors (beta-ARs) are seven-transmembrane domain, G protein-coupled receptors that transduce the cellular effects of epinephrine and norepinephrine and play a pivotal role in the vertebrate stress response. This study reports the cloning and characterization of two previously unreported beta-ARs from the rainbow trout (Oncorhynchus mykiss). Phylogenetic analysis of amino acid sequences indicates that both beta-ARs are homologs of the mammalian beta3-AR. Analysis of tissue expression patterns indicates that one of these trout beta3-adrenoceptors (beta3a-AR) is highly expressed in gill and heart, whereas the second (beta3b-AR) is highly expressed by red blood cells (RBC). Expression of the beta3b-AR in the RBC coupled with the finding of a single category of beta-AR binding sites on RBC membranes provides strong evidence for the control of the trout RBC beta-AR Na+/H+ exchanger (beta-NHE) activity by signaling through this beta3b-subtype and not through a beta1-subtype as previously proposed. The RBC-specific trout beta3b-AR exhibits binding characteristics that distinguish this receptor from each of the three pharmacologically defined categories of mammalian beta-ARs (beta1-, beta2-, and beta3-AR). This study is the first to report the presence of a beta3-AR subtype in a fish species, and the proposal that the beta3b-AR controls RBC beta-NHE activity represents a novel role for the beta3-AR subtype in vertebrates.
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Affiliation(s)
- James G Nickerson
- Dept. of Biology, Univ. of Ottawa, 150 Louis Pasteur, PO Box 450, Station A Ottawa, Ontario, Canada K1N 6N5
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103
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Nikinmaa M. Beta3-adrenergic receptors--studies on rainbow trout reveal ancient evolutionary origins and functions distinct from the thermogenic response. Am J Physiol Regul Integr Comp Physiol 2003; 285:R515-6. [PMID: 12909576 DOI: 10.1152/ajpregu.00305.2003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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104
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Hu B, Jennings LL. Orally bioavailable beta 3-adrenergic receptor agonists as potential therapeutic agents for obesity and type-II diabetes. PROGRESS IN MEDICINAL CHEMISTRY 2003; 41:167-94. [PMID: 12774694 DOI: 10.1016/s0079-6468(02)41005-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Affiliation(s)
- Baihua Hu
- Wyeth Research, P.O. Box 42528, Philadelphia, PA 19101, USA
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105
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Rathi S, Kazerounian S, Banwait K, Schulz S, Waldman SA, Rattan S. Functional and molecular characterization of beta-adrenoceptors in the internal anal sphincter. J Pharmacol Exp Ther 2003; 305:615-24. [PMID: 12606629 DOI: 10.1124/jpet.102.048462] [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
The purpose of the present study was to characterize different beta-adrenoceptors (beta-ARs) and determine their role in the spontaneously tonic smooth muscle of the internal anal sphincter (IAS). The beta-AR subtypes in the opossum IAS were investigated by functional in vitro, radioligand binding, Western blot, and reverse transcription-polymerase chain reaction (RT-PCR) studies. ZD 7114 [(S)-4-[2-hydroxy-3-phenoxypropylaminoethoxy]-N-(2-methoxyethyl)phenoxyacetamide], a selective beta(3)-AR agonist, caused a potent and concentration-dependent relaxation of the IAS smooth muscle that was antagonized by the beta(3)-AR antagonist SR 59230A [1-(2-ethylphenoxy)-3-[[(1S)-1,2,3,4-tetrahydro-1-naphthalenyl]amino]-(2S)-2-propanol hydrochloride]. Conversely, the IAS smooth muscle relaxation caused by beta(1)- and beta(2)-AR agonists (xamoterol and procaterol, respectively) was selectively antagonized by their respective antagonists CGP 20712 [(+/-)-2-hydroxy-5-[2-[[2-hydroxy-3-[4-[1-methyl-4-(trifluoromethyl)-1H-imidazol-2-yl]phenoxy]propyl]amino]ethoxy]-benzamide methanesulfonate salt] and ICI 118551. Saturation binding of [(125)I]iodocyanopindolol to beta-AR subtypes revealed the presence of a high-affinity site (K(d1) = 96.4 +/- 8.7 pM; B(max1) = 12.5 +/- 0.6 fmol/mg protein) and a low-affinity site (K(d2) = 1.96 +/- 1.7 nM; B(max2) = 58.7 +/- 4.3 fmol/mg protein). Competition binding with selective beta-AR antagonists revealed that the high-affinity site correspond to beta(1)/beta(2)-AR and the low affinity site to beta(3)-AR. Receptor binding data suggest the predominant presence of beta(3)-AR over beta(1)/beta(2)-AR. Western blot studies identified beta(1)-, beta(2)-, and beta(3)-AR subtypes. The presence of beta(1)-, beta(2)-, and beta(3)-ARs was further demonstrated by mRNA analysis using RT-PCR. The studies demonstrate a comprehensive functional and molecular characterization of beta(1)-, beta(2)-, and beta(3)-ARs in IAS smooth muscle. These studies may have important implications in anorectal and other gastrointestinal motility disorders.
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Affiliation(s)
- Sandeep Rathi
- Department of Medicine, Division of Gastroenterology and Hepatology, Jefferson Medical College, Thomas Jefferson University, 1025 Walnut Street, Room no. 901 College, Philadelphia, PA 19107, USA
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106
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Muñoz-Valle JF, Vázquez-Del Mercado M, Ruiz-Quezada S, Oregón-Romero E, Navarro-Hernández RE, Ramírez-Barragán J, Martínez-Bonilla G, Bernard-Medina G, Bastidas-Ramírez BE, Ruiz-Madrigal B, Panduro A. Polymorphism of the beta3-adrenergic receptor and lipid profile in patients with rheumatoid arthritis and systemic lupus erythematosus treated with chloroquine. Rheumatol Int 2003; 23:99-103. [PMID: 12739037 DOI: 10.1007/s00296-002-0266-z] [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] [Received: 01/24/2002] [Accepted: 10/22/2002] [Indexed: 10/27/2022]
Abstract
We investigated the effect of beta 3-adrenergic receptor (beta(3)AR) polymorphism on lipid profiles in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) treated with chloroquine. One hundred sixty-eight subjects were classified into three groups: 61 RA patients, 57 SLE patients, and 50 healthy subjects. All patients fulfilled the 1987 and 1982 classification criteria for RA and SLE, respectively, of the American College of Rheumatology. Demographic data and clinical characteristics of the patients were registered. Fasting lipid profile determination and leukocyte genomic DNA isolation from peripheral blood was performed in all the participants. Screening of the beta(3)-AR gene polymorphic region (exon 1) was done by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Quantitative and qualitative variables were analyzed using analysis of variance (ANOVA) with the LSD and chi(2) tests, respectively. An association between the arg64/arg64 beta(3)-AR genotype and high levels of triglycerides (TG) and very low-density lipoprotein cholesterol (VLDL-c) was found in three RA patients ( P=0.01), two of them taking chloroquine. Arg64/arg64 beta(3)-AR polymorphism may contribute to increased TG and VLDL-c in RA patients, independently of chloroquine treatment.
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Affiliation(s)
- J F Muñoz-Valle
- Laboratorio de Inmunología, Centro Universitario de Ciencias de la Salud, Sierra Mojada Street #950, P.O. Box 2-500, Guadalajara, Jalisco, Mexico C.P. 44340
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107
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Cirino G, Sorrentino R, di Villa Bianca RD, Popolo A, Palmieri A, Imbimbo C, Fusco F, Longo N, Tajana G, Ignarro LJ, Mirone V. Involvement of beta 3-adrenergic receptor activation via cyclic GMP- but not NO-dependent mechanisms in human corpus cavernosum function. Proc Natl Acad Sci U S A 2003; 100:5531-6. [PMID: 12707413 PMCID: PMC154379 DOI: 10.1073/pnas.0931347100] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The beta(3)-adrenoreceptor plays a major role in lipolysis but the role and distribution of beta(3)-receptors in other specific sites have not been extensively studied. beta(3)-adrenergic receptors are present not only in adipose tissue but also in human gall bladder, colon, prostate, and skeletal muscle. Recently, beta(3)-adrenergic receptor stimulation was shown to elicit vasorelaxation of rat aorta through the NO-cGMP signal transduction pathway. Here we show that beta(3)-receptors are present in human corpus cavernosum and are localized mainly in smooth muscle cells. After activation by a selective beta(3)-adrenergic receptor agonist, BRL 37344, there was a cGMP-dependent but NO-independent vasorelaxation that was selectively blocked by a specific beta(3)-receptor antagonist. In addition, we report that the human corpus cavernosum exhibits basal beta(3)-receptor-mediated vasorelaxant tone and that beta(3)-receptor activity is linked to inhibition of the RhoA/Rho-kinase pathway. These observations indicate that beta(3)-receptors may play a physiological role in mediating penile erection and, therefore, could represent a therapeutic target for treatment of erectile dysfunction.
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Affiliation(s)
- Giuseppe Cirino
- Dipartimento di Farmacologia Sperimentale, Facoltà di Medicina Università di Napoli-Federico II, 80131 Naples, Italy
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108
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Harada H, Hirokawa Y, Suzuki K, Hiyama Y, Oue M, Kawashima H, Yoshida N, Furutani Y, Kato S. Novel and potent human and rat beta3-adrenergic receptor agonists containing substituted 3-indolylalkylamines. Bioorg Med Chem Lett 2003; 13:1301-5. [PMID: 12657269 DOI: 10.1016/s0960-894x(03)00073-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A novel series of 2-(3-indolyl)alkylamino-1-(3-chlorophenyl)ethanols was prepared and evaluated for in vitro ability to stimulate cAMP production in Chinese hamster ovary cells expressing cloned human beta(3)-AR. The optically active 30a was found to be the most potent and selective human beta(3)-AR agonist in this series with an EC(50) value of 0.062nM. In addition, 30a selectivity for human beta(3)-AR was 210-fold and 103-fold that for human beta(2)-AR and beta(1)-AR, respectively. Furthermore, 30a showed potent agonistic activity at rat beta(3)-AR.
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Affiliation(s)
- Hiroshi Harada
- Chemistry Research Laboratories, Dainippon Pharmaceutical Co., Ltd., Enoki, Suita, Japan.
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109
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Opposite action of beta1- and beta2-adrenergic receptors on Ca(V)1 L-channel current in rat adrenal chromaffin cells. J Neurosci 2003. [PMID: 12514203 DOI: 10.1523/jneurosci.23-01-00073.2003] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Voltage-gated Ca(2+) channels of chromaffin cells are modulated by locally released neurotransmitters through autoreceptor-activated G-proteins. Clear evidence exists in favor of a Ca(2+) channel gating inhibition mediated by purinergic, opioidergic, and alpha-adrenergic autoreceptors. Few and contradictory data suggest also a role of beta-adrenergic autoreceptors (beta-ARs), the action of which, however, remains obscure. Here, using patch-perforated recordings, we show that rat chromaffin cells respond to the beta-AR agonist isoprenaline (ISO) by either upmodulating or downmodulating the amplitude of Ca(2+) currents through two distinct modulatory pathways. ISO (1 microm) could cause either fast inhibition (approximately 25%) or slow potentiation (approximately 25%), or a combination of the two actions. Both effects were completely prevented by propranolol. Slow potentiation was more evident in cells pretreated with pertussis toxin (PTX) or when beta(1)-ARs were selectively stimulated with ISO + ICI118,551. Potentiation was absent when the beta(2)-AR-selective agonist zinterol (1 microm), the protein kinase A (PKA) inhibitor H89, or nifedipine was applied, suggesting that potentiation is associated with a PKA-mediated phosphorylation of L-channels (approximately 40% L-current increase) through beta(1)-ARs. The ISO-induced inhibition was fast and reversible, preserved in cell treated with H89, and mimicked by zinterol. The action of zinterol was mostly on L-channels (38% inhibition). Zinterol action preserved the channel activation kinetics, the voltage-dependence of the I-V characteristic, and was removed by PTX, suggesting that beta(2)AR-mediated channel inhibition was mainly voltage independent and coupled to G(i)/G(o)-proteins. Sequential application of zinterol and ISO mimicked the dual action (inhibition/potentiation) of ISO alone. The two kinetically and pharmacologically distinct beta-ARs signaling uncover alternative pathways, which may serve the autocrine control of Ca(2+)-dependent exocytosis and other related functions of rat chromaffin cells.
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110
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Hücking K, Hamilton-Wessler M, Ellmerer M, Bergman RN. Burst-like control of lipolysis by the sympathetic nervous system in vivo. J Clin Invest 2003; 111:257-64. [PMID: 12531882 PMCID: PMC151855 DOI: 10.1172/jci14466] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Rapid oscillations of visceral lipolysis have been reported. To examine the putative role of the CNS in oscillatory lipolysis, we tested the effects of beta(3)-blockade on pulsatile release of FFAs. Arterial blood samples were drawn at 1-minute intervals for 120 minutes from fasted, conscious dogs (n = 7) during the infusion of saline or bupranolol (1.5 micro g/kg/min), a high-affinity beta(3)-blocker. FFA and glycerol time series were analyzed and deconvolution analysis was applied to estimate the rate of FFA release. During saline infusion FFAs and glycerol oscillated in phase at about eight pulses/hour. Deconvolution analysis showed bursts of lipolysis (nine pulses/hour) with time-dependent variation in burst frequency. Bupranolol completely removed rapid FFA and glycerol oscillations. Despite removal of lipolytic bursts, plasma FFAs (0.31 mM) and glycerol (0.06 mM) were not totally suppressed and deconvolution analysis revealed persistent non-oscillatory lipolysis (0.064 mM/min). These results show that lipolysis in the fasting state consists of an oscillatory component, which appears to be entirely dependent upon sympathetic innervation of the adipose tissue, and a non-oscillatory, constitutive component, which persists despite beta(3)-blockade. The extinction of lipid fuel bursts by beta(3)-blockade implies a role for the CNS in the maintenance of cyclic provision of lipid fuels.
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Affiliation(s)
- Katrin Hücking
- Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, USA
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111
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Akimoto Y, Horinouchi T, Tanaka Y, Koike K. The .BETA.3-Adrenoceptor-Mediated Relaxation Induced by Dopamine in Guinea Pig Taenia Caecum. J Smooth Muscle Res 2003; 39:39-45. [PMID: 14572171 DOI: 10.1540/jsmr.39.39] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The mechanisms of the beta-adrenoceptor-mediated relaxation induced by dopamine in guinea pig taenia caecum were examined. The relaxant response to dopamine was unaffected by propranolol (10(-8)-10(-5) M) or phentolamine (10(-8)-10(-5) M). Atenolol (3 x 10(-7)-3 x 10(-4) M), butoxamine (10(-7)-10(-4) M), prazosin (10(-8)-10(-5) M), yohimbine (10(-8)-10(-5) M), SCH 23390 (10(-8)-10(-5) M) and haloperidol (10(-8)-10(-5) M) had no effect on the potency of dopamine. The response to dopamine was antagonized in a concentration-dependent manner by bupranolol (3 x 10(-6)-3 x 10(-5) M), and Schild plot of the data revealed the pA2 value of 5.55 and the slope of the regression line was 1.13. These results suggest that the relaxant response to dopamine in the guinea pig taenia caecum is mainly mediated by the beta3-adrenoceptors.
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Affiliation(s)
- Yurie Akimoto
- Department of Chemical Pharmacology, Toho University School of Pharmaceutical Sciences, 2-2-1, Miyama, Funabashi, Chiba 274-8510, Japan.
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112
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Sarma DNK, Banwait K, Basak A, DiMarino AJ, Rattan S. Inhibitory effect of beta3-adrenoceptor agonist in lower esophageal sphincter smooth muscle: in vitro studies. J Pharmacol Exp Ther 2003; 304:48-55. [PMID: 12490574 DOI: 10.1124/jpet.102.040501] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We investigated the effects of (R,R)-5-[2-[2-3-chlorophenyl)-2-hydroxyethyl] - amino]propyl] - 1,3 - benzodioxole - 2, 2 - dicarboxylate (CL 316243) (a typical beta3-agonist) on the spontaneously tonic smooth muscle of the lower esophageal sphincter (LES). Studies were carried out in smooth muscle strips and smooth muscle cells (SMCs) of opossum LES. Isometric tension was recorded in the basal state and after CL 316243, and before and after beta3-antagonist (S)-N-[4-[2-[[3-[-(acetamidomethyl)phenoxy]-2-hydroxypropyl]amino]ethyl]phenyl]benzenesulfonamide (L 748337) and nonselective antagonist propranolol. In some experiments, the effects of nonadrenergic noncholinergic (NANC) nerve activation by electrical field stimulation (EFS) were also examined. The effects of CL 316243 were compared with those of nonselective beta-agonist isoproterenol. CL 316243 caused a concentration-dependent relaxation of the LES smooth muscle. The relaxant action of CL 316243 was determined to be directly at the smooth muscle because it remained unmodified by the neurotoxin tetrodotoxin and other neurohumoral antagonists, and also was observed in the SMCs. L 748337 selectively antagonized the relaxant effect of CL 316243 and, conversely, had no significant effect on the inhibitory actions of isoproterenol. CL 316243 (1 x 10(-8) M) caused an augmentation of NANC relaxation in the LES. Another beta3-agonist, (S)-4-[hydroxy-3-phenoxy-propylamino-ethoxy]-N-(2-methoxyethyl)-phenoxyacetamide (ZD 7114), also caused concentration-dependent full relaxation of the LES that was selectively antagonized by beta3-anatagonist 3-(2-ethylphenoxy)-1-[(1S)1,2,3,4-tetrahydronaphth-1-ylaminol]-(2S)-2-propanol oxalate (SR 59230A). These studies defined the effects of characteristic inhibitory beta3-adrenoceptors in the spontaneously tonic LES smooth muscle and suggested a potential therapeutic role in the esophageal motility disorders characterized by hypertensive LES.
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Affiliation(s)
- D N K Sarma
- Department of Medicine, Division of Gastroenterology and Hepatology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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113
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Dimarino M, Banwait K, Rattan S, Cohen S, DiMarino AJ. Beta3 adrenergic stimulation inhibits the opossum lower esophageal sphincter. Gastroenterology 2002; 123:1508-15. [PMID: 12404226 DOI: 10.1053/gast.2002.36564] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS Previous studies have identified adrenergic receptor sites in the lower esophageal sphincter (LES) of animals and humans. A beta3 adrenoceptor has been identified and cloned. The binding site for this receptor has been found in the rat LES in vitro. The aim of the study was to assess the role of a specific beta3 agonist (CL316243) on LES pressure (LESP) in vivo. METHODS Anesthetized adult opossums were given CL316243 and isoproterenol intravenously as boluses before and after continuous infusion of L748337 (a specific beta3 antagonist), propranolol, and bethanechol. Blood pressure, heart rate, and LESP were continuously recorded. RESULTS CL316243 caused a dose-dependent maximal inhibition of LESP of 88.5% +/- 4.8%. The mean duration of inhibition was 62.2 +/- 9.2 minutes with minimal change in cardiovascular parameters. Isoproterenol caused dose-dependent maximal inhibition of 89.4% +/- 4.7% with mean duration of action of 5.1 +/- 0.9 minutes but was associated with significant hypotension and tachycardia. L748337 and propranolol significantly blocked the effects of CL316243 and isoproterenol, respectively. CL316243 and isoproterenol inhibited the bethanechol-mediated hypertensive LES. CONCLUSIONS (1) A selective beta3 agonist, CL316243, caused significant, prolonged, and dose-dependent inhibition of LESP and, unlike isoproterenol, had minimal effect on heart rate and mean arterial pressure. (2) The beta3 antagonist, L748337, selectively inhibited CL316243 without altering the isoproterenol response. (3) CL316243 and isoproterenol both caused inhibition of cholinergic-mediated hypertensive LESP.
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Affiliation(s)
- Michael Dimarino
- Division of Gastroenterology and Hepatology, Department of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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114
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Akimoto Y, Horinouchi T, Tanaka Y, Koike K. The beta2- and beta3-adrenoceptor-mediated relaxation induced by fenoterol in guinea pig taenia caecum. J Smooth Muscle Res 2002; 38:145-51. [PMID: 12596892 DOI: 10.1540/jsmr.38.145] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Fenoterol, a beta2-adrenoceptor selective agonist, belongs to the arylethanolamine class. To understand the receptor subtypes responsible for beta-adrenoceptor-mediated relaxation of guinea pig taenia caecum, we investigated the effect of fenoterol. Fenoterol caused concentration-dependent relaxation of the guinea pig taenia caecum. Propranolol, bupranolol and butoxamine produced shifts of the concentration-response curve for fenoterol. Schild regression analyses carried out for propranolol, butoxamine and bupranolol against fenoterol gave pA2 values of 8.41, 6.33 and 8.44, respectively. However, in the presence of 3 x 10(-4) M atenolol, 10(-4) M butoxamine and 10(-6) M phentolamine to block the beta1-, beta2- and a-adrenoceptor effects, respectively, Schild regression analysis carried out for bupranolol against fenoterol gave pA2 values of 5.80. These results suggest that the relaxant response to fenoterol in the guinea pig taenia caecum is mediated by both the beta2- and the beta3-adrenoceptors.
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Affiliation(s)
- Yurie Akimoto
- Department of Chemical Pharmacology, Toho University School of Pharmaceutical Sciences, 2-2-1, Miyama, Funabashi, Chiba 274-8510, Japan.
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115
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Steffan RJ, Ashwell MA, Solvibile WR, Matelan E, Largis E, Han S, Tillet J, Mulvey R. Novel substituted 4-aminomethylpiperidines as potent and selective human β3-agonists. Part 2: Arylethanolaminomethylpiperidines. Bioorg Med Chem Lett 2002; 12:2963-7. [PMID: 12270184 DOI: 10.1016/s0960-894x(02)00608-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The synthesis and SAR of a series of beta3 adrenoreceptor agonists based on a novel template derived from 4-aminomethylpiperidine coupled with a common pharmacophore, arylethylamine, is described. This combination led to the identification of human beta3 adrenoreceptor agonists with in vivo activity in a transgenic mouse model.
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Affiliation(s)
- Robert J Steffan
- Chemical Sciences, Wyeth Research, 500 Arcola Rd, Collegeville, PA 19426, USA.
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116
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Steffan RJ, Ashwell MA, Solvibile WR, Matelan E, Largis E, Han S, Tillet J, Mulvey R. Novel substituted 4-aminomethylpiperidines as potent and selective human β3-agonists. Part 1: aryloxypropanolaminomethylpiperidines. Bioorg Med Chem Lett 2002; 12:2957-61. [PMID: 12270183 DOI: 10.1016/s0960-894x(02)00607-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The synthesis and SAR of a series of human beta3 adrenoreceptor agonists based on a template derived from a common pharmacophore coupled with 4-aminomethylpiperidine is described. Potent and selective agents were identified such as 26 that was in vitro active in CHO cells expressing human beta3-AR (EC50=49 nM, IA=1.1), and in vivo active in a transgenic mouse model.
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Affiliation(s)
- Robert J Steffan
- Chemical Sciences, Wyeth Research, 500 Arcola Rd, Collegeville, PA 19426, USA.
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117
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Rautureau Y, Toumaniantz G, Serpillon S, Jourdon P, Trochu JN, Gauthier C. Beta 3-adrenoceptor in rat aorta: molecular and biochemical characterization and signalling pathway. Br J Pharmacol 2002; 137:153-61. [PMID: 12208771 PMCID: PMC1573490 DOI: 10.1038/sj.bjp.0704867] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
1. We have previously demonstrated that beta(3)-adrenoceptor (beta(3)-AR) stimulation induces endothelium-dependent vasorelaxation in rat aorta through the activation of an endothelial NO synthase associated with an increase in intracellular cGMP. The aim of the present study was to localise beta(3)-AR to confirm our functional study and to complete the signalling pathway of beta(3)-AR in rat aorta. 2. By RT-PCR, we have detected beta(3)-AR transcripts both in aorta and in freshly isolated endothelial cells. The absence of markers for adipsin or hormone-sensitive lipase in endothelial cells excluded the presence of beta(3)-AR from adipocytes. The localization of beta(3)-AR in aortic endothelial cells was confirmed by immunohistochemistry using a rat beta(3)-AR antibody. 3. To identify the G protein linked to beta(3)-AR, experiments were performed in rat pre-treated with PTX (10 microg kg(-1)), a G(i/0) protein inhibitor. The blockage of G(i/0) protein by PTX was confirmed by the reduction of vasorelaxation induced by UK 14304, a selective alpha(2)-AR agonist. The cumulative concentration-response curve for SR 58611A, a beta(3)-AR agonist, was not significantly modified on aorta rings from PTX pre-treated rats. 4. At the same level of contraction, the relaxations induced by 10 microM SR 58611A were significantly reduced in 30 mM-KCl pre-constricted rings (E(max)=16.7+/-8.4%, n=5), in comparison to phenylephrine (0.3 microM) pre-constricted rings (E(max)=49.11+/-11.0%, n=5, P<0.05). In addition, iberotoxin (0.1 microM), glibenclamide (1 microM) and 4-aminopyridine (1 mM), selective potassium channels blockers of K(Ca), K(ATP), and K(v) respectively, decreased the SR 58611A-mediated relaxation. 5. We conclude that beta(3)-AR is preferentially expressed in rat aortic endothelial cells. Beta(3)-AR-mediated aortic relaxation is independent of G(i/0) proteins stimulation, but results from the activation of several potassium channels, K(Ca), K(ATP), and K(v).
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Affiliation(s)
- Yohann Rautureau
- Laboratoire de Physiopathologie et de Pharmacologie Cellulaires et Moléculaires, INSERM U533, Hôtel-Dieu, Nantes, France
| | - Gilles Toumaniantz
- Laboratoire de Physiopathologie et de Pharmacologie Cellulaires et Moléculaires, INSERM U533, Hôtel-Dieu, Nantes, France
| | - Sabrina Serpillon
- Laboratoire de Physiopathologie et de Pharmacologie Cellulaires et Moléculaires, INSERM U533, Hôtel-Dieu, Nantes, France
| | - Philippe Jourdon
- Laboratoire de Physiopathologie et de Pharmacologie Cellulaires et Moléculaires, INSERM U533, Hôtel-Dieu, Nantes, France
| | - Jean-Noël Trochu
- Laboratoire de Physiopathologie et de Pharmacologie Cellulaires et Moléculaires, INSERM U533, Hôtel-Dieu, Nantes, France
| | - Chantal Gauthier
- Laboratoire de Physiopathologie et de Pharmacologie Cellulaires et Moléculaires, INSERM U533, Hôtel-Dieu, Nantes, France
- Faculté des Sciences et Techniques, Université de Nantes, France
- Author for correspondence:
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Abstract
The detrusor muscle contains beta-adrenoceptors (beta-AR), and 2 subtypes-beta1-AR and beta2-AR-have been identified in most species. Although beta2-AR has an important role in muscle relaxation via activation of adenylate cyclase, evidence suggests that a third subtype, beta3-AR, which is implicated in metabolic functions of endogenous catecholamines, mediates relaxation of human detrusor muscle. There is a predominant expression of beta3-AR messenger RNA (mRNA) in human bladder tissue, with 97% of total beta-AR mRNA being represented by the beta3-AR subtype and only 1.5% and 1.4% by the beta1-AR and beta2-AR subtypes, respectively. Functionally, selective beta3-AR agonists relax human isolated detrusor, whereas selective beta1-AR/beta2-AR agonists do not. Isoproterenol-induced relaxation is inhibited by selective beta3-AR antagonists but not by selective beta1-AR or beta2-AR antagonists. In animal models, beta3-AR agonists increase bladder capacity and have only weak cardiovascular side effects. Although this evidence points toward the clinical utility of beta3-AR agonists as therapy for overactive bladder, clinical trials of beta3-AR agonists identified in animal models as antiobesity agents indicate side effects of tremor and tachycardia. Development of compounds with high selectivity for the human beta3-AR, identified by screening techniques using cell lines transfected with the human beta1-AR, beta2-AR, and beta3-AR genes, may mitigate such problems. Together with the preliminary finding that 49% (21 of 43) of patients with idiopathic detrusor instability have a tryptophan 64 arginine mutation of the beta3-AR gene, which may be a useful genetic marker, evidence points toward beta3-AR being a therapeutic target for treatment of overactive bladder disorder.
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Affiliation(s)
- Osamu Yamaguchi
- Department of Urology, Fukushima Medical University, Fukushima, Japan.
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Tanaka N, Tamai T, Mukaiyama H, Hirabayashi A, Muranaka H, Ishikawa T, Akahane S, Akahane M. Beta(3)-adrenoceptor agonists for the treatment of frequent urination and urinary incontinence: 2-[4-(2-[[(1S,2R)-2-hydroxy-2-(4-hydroxyphenyl)-1-methylethyl]amino]ethyl)phenoxy]-2-methylpropionic acid. Bioorg Med Chem 2001; 9:3265-71. [PMID: 11711302 DOI: 10.1016/s0968-0896(01)00240-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In a search for novel analogues of beta(3)-adrenoceptor (AR) agonists relaxing the bladder for treatment of urinary dysfunction, 2-[4-(2-[[(1S,2R)-2-hydroxy-2-(4-hydroxyphenyl)-1-methylethyl]amino]ethyl)phenoxy]-2-methylpropionic acids (1a-e), into which a fibrate-like structure had been incorporated, were synthesised. Compound 1a was found to be a selective beta(3)-AR agonist in functional assays using the ferret detrusor (beta(3)-AR), rat uterus (beta(2)-AR), and rat atrium (beta(1)-AR); beta(3): EC(50)=7.8 nM, beta(2): IC(50)=7,300 nM, beta(1): EC(20)=23,000 nM. The introduction of a chlorine atom or methyl substituent at the ortho-position on the phenyl ring of 1a further improved beta(3)-AR selectivity. In an in vivo study, 1a lowered intrabladder pressure (ED(50)=31 microg/kg) in rats, without increasing heart rate, in keeping with the in vitro results. Consequently, it is proposed that 1a and its analogues (1b-e), possess beta(3)-AR agonistic activity in the absence of undesirable beta(1)- or beta(2)-AR mediated actions, and may be useful for clinical treatment and pharmacological studies.
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Affiliation(s)
- N Tanaka
- Central Research Laboratory, Kissei Pharmaceutical Company Ltd., 4365-1, Hotaka, Nagano, 399-8304, Japan.
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120
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Kohout TA, Takaoka H, McDonald PH, Perry SJ, Mao L, Lefkowitz RJ, Rockman HA. Augmentation of cardiac contractility mediated by the human beta(3)-adrenergic receptor overexpressed in the hearts of transgenic mice. Circulation 2001; 104:2485-91. [PMID: 11705829 DOI: 10.1161/hc4501.098933] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Stimulation of beta(1)- and beta(2)-adrenergic receptors (ARs) in the heart results in positive inotropy. In contrast, it has been reported that the beta(3)AR is also expressed in the human heart and that its stimulation leads to negative inotropic effects. METHODS AND RESULTS To better understand the role of beta(3)ARs in cardiac function, we generated transgenic mice with cardiac-specific overexpression of 330 fmol/mg protein of the human beta(3)AR (TGbeta(3) mice). Hemodynamic characterization was performed by cardiac catheterization in closed-chest anesthetized mice, by pressure-volume-loop analysis, and by echocardiography in conscious mice. After propranolol blockade of endogenous beta(1)- and beta(2)ARs, isoproterenol resulted in an increase in contractility in the TGbeta(3) mice (30%), with no effect in wild-type mice. Similarly, stimulation with the selective human beta(3)AR agonist L-755,507 significantly increased contractility in the TGbeta(3) mice (160%), with no effect in wild-type mice, as determined by hemodynamic measurements and by end-systolic pressure-volume relations. The underlying mechanism of the positive inotropy incurred with L-755,507 in the TGbeta(3) mice was investigated in terms of beta(3)AR-G-protein coupling and adenylyl cyclase activation. Stimulation of cardiac membranes from TGbeta(3) mice with L-755,507 resulted in a pertussis toxin-insensitive 1.33-fold increase in [(35)S]GTPgammaS loading and a 1.6-fold increase in adenylyl cyclase activity. CONCLUSIONS Cardiac overexpression of human beta(3)ARs results in positive inotropy only on stimulation with a beta(3)AR agonist. Overexpressed beta(3)ARs couple to G(s) and activate adenylyl cyclase on agonist stimulation.
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Affiliation(s)
- T A Kohout
- Howard Hughes Medical Institute, Department of Medicine, Duke University Medical Center, Durham, NC, USA
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121
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Nagatomo T, Ohnuki T, Ishiguro M, Ahmed M, Nakamura T. Beta-adrenoceptors: three-dimensional structures and binding sites for ligands. JAPANESE JOURNAL OF PHARMACOLOGY 2001; 87:7-13. [PMID: 11676201 DOI: 10.1254/jjp.87.7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Recent progress in analyzing the structures and functions of G-protein coupled receptors (GPCRs) including beta-adrenoceptors (beta-ARs) has been made by pharmacological, physiological and molecular biological techniques. The three-dimensional (3D) structures, interaction sites with ligands and conformational changes of these receptor subtypes due to ligand binding are now better understood by the simulation of these receptors using computer-aided molecular modeling. Based on these techniques, numbers and conformations of amino acid sequences of each subtype (beta1-, beta2- and beta3-ARs) were defined and also interaction sites or modes of interaction between ligands and beta-ARs could be analyzed three-dimensionally. In addition, simulation of 3D structures of beta-ARs by molecular modeling could clearly determine the limited size, space or pocket for fitting with ligands. These studies will give some clues for the clarification of other GPCRs. Thus, this review summarizes current findings on chemical structures of ligands, amino acid sequences, 3D structures and important amino acids of beta-AR subtypes for interacting with ligands obtained from mutagenesis, chimeric studies and molecular modeling techniques.
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Affiliation(s)
- T Nagatomo
- Department of Pharmacology, Niigata College of Pharmacy, Japan.
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122
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Hu B, Ellingboe J, Han S, Largis E, Lim K, Malamas M, Mulvey R, Niu C, Oliphant A, Pelletier J, Singanallore T, Sum FW, Tillett J, Wong V. Novel (4-piperidin-1-yl)-phenyl sulfonamides as potent and selective human beta(3) agonists. Bioorg Med Chem 2001; 9:2045-59. [PMID: 11504641 DOI: 10.1016/s0968-0896(01)00114-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A series of novel (4-piperidin-1-yl)-phenyl sulfonamides was prepared and evaluated for their biological activity on the human beta(3)-adrenergic receptor (AR). Replacement of the 3,4-dihydroxyl group of the catechol moiety with 4-hydroxyl-3-methyl sulfonamide on the left-hand side of the compounds resulted in a number of potent full agonists at the beta(3) receptor. Modification of the right-hand side of the compounds by incorporation of a free carboxylic acid resulted in a few potent human beta(3) agonists with low affinities for beta(1)- and beta(2)-ARs. N-Alkyl substitution on the 4-piperidin-1-yl-phenylamine further increased the beta(3) potency while maintaining the selectivity. For example, sulfonamide 48 is a potent full beta(3) agonist (EC(50)=0.004 microM, IA=1.0) with > 500-fold selectivity over beta(1)- and beta(2)-ARs.
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Affiliation(s)
- B Hu
- Chemical Sciences, Wyeth-Ayerst Research, Pearl River, NY 10965, USA.
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123
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Danner I, Escande D, Gauthier C. Beta(3)-adrenoceptors control Cl(-) conductance in rabbit nasal epithelium. Eur J Pharmacol 2001; 422:203-7. [PMID: 11430932 DOI: 10.1016/s0014-2999(01)01060-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
We have investigated the effects of beta(3)-adrenoceptor stimulation in vivo on nasal epithelium. We have recorded the transepithelial potential difference in New Zealand white rabbit nostrils. Superfusion of the nasal epithelial surface with a Cl(-)-free medium supplemented with amiloride, hyperpolarized the nasal potential difference. Isoprenaline produced a hyperpolarization of the nasal potential difference that was not prevented by nadolol, a potent beta(1)-/beta(2)-adrenoceptor antagonist, but was abolished by bupranolol, a nonselective beta(1-3)-adrenoceptor antagonist. SR 58611 ((RS)-N-[(25)-7-ethoxycarbonylmethoxy-1,2,3,4-tetrahydronapht-2-yl]-(2R)-2-(3-chlorophenyl)-2 hydroethanamine hydrochloride) and CGP 12177 (4-[3-t-butylamino-2-hydroxypropoxy]benzimidazol-2-1), a preferential and a partial beta(3)-adrenoceptor agonists, respectively, also produced hyperpolarization of the nasal potential difference. SR 59230 (3-(2-ethylphenoxy)-1-[(1S)1,2,3,4-tetrahydronaphth-1-ylaminol]-(2S)-2-propanol oxalate), a selective beta(3)-adrenoceptor antagonist, abolished the effects of CGP 12177. We conclude that beta(3)-adrenoceptor stimulation resulted in modifications in the nasal potential difference. These findings strengthen the view that beta(3)-adrenoceptors are implicated in controlling water and salt transport in the normal respiratory epithelium.
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Affiliation(s)
- I Danner
- Laboratoire de Physiopathologie et de Pharmacologie Cellulaires et Moléculaires, INSERM U533, Hôtel-Dieu, Nantes, France
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124
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β 3 -Adrenergic receptor ligands: insight into structure–activity relationships using Monte-Carlo conformational analysis in water. Tetrahedron 2001. [DOI: 10.1016/s0040-4020(00)01165-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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125
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Butz P, Kroemer RT, Macleod NA, Simons JP. Conformational Preferences of Neurotransmitters: Ephedrine and Its Diastereoisomer, Pseudoephedrine. J Phys Chem A 2001. [DOI: 10.1021/jp002862s] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Patrick Butz
- Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom, and Department of Chemistry, Queen Mary and Westfield College, University of London, Mile End Road, London E1 4NS, United Kingdom
| | - Romano T. Kroemer
- Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom, and Department of Chemistry, Queen Mary and Westfield College, University of London, Mile End Road, London E1 4NS, United Kingdom
| | - Neil A. Macleod
- Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom, and Department of Chemistry, Queen Mary and Westfield College, University of London, Mile End Road, London E1 4NS, United Kingdom
| | - John P. Simons
- Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom, and Department of Chemistry, Queen Mary and Westfield College, University of London, Mile End Road, London E1 4NS, United Kingdom
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126
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Lowe WL, Rotimi CN, Luke A, Guo X, Zhu X, Comuzzie AG, Schuh TS, Halbach S, Kotlar TJ, Cooper RS. The beta 3-adrenergic receptor gene and obesity in a population sample of African Americans. Int J Obes (Lond) 2001; 25:54-60. [PMID: 11244458 DOI: 10.1038/sj.ijo.0801487] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE To examine the role of the Trp64Arg polymorphism in the beta 3-adrenergic receptor gene and the beta 3-adrenergic receptor gene locus in obesity-related traits in African Americans. SUBJECTS A total of 687 individuals representing 193 African American families who were residents of metropolitan Chicago. MEASUREMENTS Genotyping of the Trp64Arg polymorphism in the beta 3-adrenergic receptor gene and three microsatellite markers flanking the beta 3-adrenergic receptor gene (ADRB3) locus and measuring various obesity-related traits, including body mass index (BMI), fat-free mass, fat mass, percentage fat mass, waist circumference and serum lipid levels. RESULTS The prevalence of obesity (defined as body mass index > or = 30 kg/m(2)) in the population was 27.3% and 51.2% in men and women, respectively. The frequency of the Arg64 allele was 10.0%. Multivariate regression analyses confirmed the existence of a significant contribution of familial variance to each of the five obesity-related traits noted above. Likelihood ratio statistics computed in a multivariate regression analysis failed to demonstrate a significant association between the Arg64 allele and any of the five obesity-related traits. Single and multipoint analyses using extended Haseman--Elston regression analyses failed to demonstrate suggestive evidence of linkage of three microsatellite markers that flank the beta 3-adrenergic receptor gene to BMI, percentage body fat, waist circumference or serum leptin levels. CONCLUSION Given the contribution of familial variance to obesity-related traits in this population, neither the null finding for the Arg64 allele nor the lack of evidence of linkage of the ADRB3 locus to obesity-related traits could be attributed to lack of transmissibility of the traits suggesting that neither the Arg64 variant of the beta 3-adrenergic receptor gene nor another genetic variant in or near the ADRB3 locus contribute significantly to familial aggregation of obesity-related traits in African Americans. International Journal of Obesity (2001) 25, 54-60
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Affiliation(s)
- W L Lowe
- Department of Medicine, Northwestern University Medical School and VA Chicago Healthcare System, Lakeside Division, Chicago, Illinois 60611, USA.
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127
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Konkar AA, Nikulin VI, De Los Angeles J, Hong SS, Fertel RH, Miller DD, Feller DR. Biochemical activities of trimetoquinol analogs at human beta(1)- and beta(3)-adrenergic receptors. Pharmacology 2001; 62:45-55. [PMID: 11150922 DOI: 10.1159/000056071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The biochemical activities of trimetoquinol (TMQ) analogs were evaluated at the human beta(1)- and beta(3)-adrenergic receptor (AR) subtypes expressed in Chinese hamster ovary cells. In radioligand binding assays, the 1-benzyl iodine-substituted analogs exhibited higher binding affinities at both beta(1)- and beta(3)-AR subtype as compared to TMQ. In cAMP accumulation assays, these analogs exhibited high potencies at both beta(1)- and beta(3)-AR. The 3',5'-diiodo-4'-amino analog of TMQ was the most potent beta(3)-AR agonist, 17-fold more potent at the beta(3)-AR versus the beta(1)-AR. Masking of the 6,7-dihydroxy group of the catechol ring of 3',5'-diiodo-4'-acetamido analog of TMQ, a potent beta(1)- and beta(3)-AR agonist, abolished activity at both beta-AR subtypes. Furthermore, substitution of a strong electron withdrawing group such as the trifluoromethyl moiety at the 1-benzyl ring of TMQ dramatically decreased potency at beta(1)- and beta(3)-AR compared to TMQ. Replacement of the 1-benzyl ring of TMQ with a naphthalene ring did not alter affinity but reduced potency of resulting 1-naphthylmethyl and 2-naphthylmethyl analogs at beta(1)- and beta(3)-AR compared to TMQ. Our results define the structural and electronic properties of substituents on TMQ necessary for potent activation of beta(1)- and beta(3)-AR and suggest that further modifications of the 1-benzyl iodine-substituted analogs may yield potent beta(3)-AR agonists.
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Affiliation(s)
- A A Konkar
- Division of Pharmacology, College of Pharmacy, The Ohio State University, Columbus, Ohio, USA
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128
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Cao W, Luttrell LM, Medvedev AV, Pierce KL, Daniel KW, Dixon TM, Lefkowitz RJ, Collins S. Direct binding of activated c-Src to the beta 3-adrenergic receptor is required for MAP kinase activation. J Biol Chem 2000; 275:38131-4. [PMID: 11013230 DOI: 10.1074/jbc.c000592200] [Citation(s) in RCA: 159] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Both beta(2)- and beta(3)-adrenergic receptors (ARs) are able to activate the extracellular signal-regulated kinase (ERK) pathway. We previously showed that c-Src is required for ERK activation by beta(2)AR and that it is recruited to activated beta(2)AR through binding of the Src homology 3 (SH3) domain to proline-rich regions of the adapter protein beta-arrestin1. Despite the absence of sites for phosphorylation and beta-arrestin binding, ERK activation by beta(3)AR still requires c-Src. Agonist activation of beta(2)AR, but not beta(3)AR, led to redistribution of green fluorescent protein-tagged beta-arrestin to the plasma membrane. In beta-arrestin-deficient COS-7 cells, beta-agonist-dependent co-precipitation of c-Src with the beta(2)AR required exogenous beta-arrestin, but activated beta(3)AR co-precipitated c-Src in the absence or presence of beta-arrestin. ERK activation and Src co-precipitation with beta(3)AR also occurred in adipocytes in an agonist-dependent and pertussis toxin-sensitive manner. Protein interaction studies show that the beta(3)AR interacts directly with the SH3 domain of Src through proline-rich motifs (PXXP) in the third intracellular loop and the carboxyl terminus. ERK activation and Src co-precipitation were abolished in cells expressing point mutations in these PXXP motifs. Together, these data describe a novel mechanism of ERK activation by a G protein-coupled receptor in which the intracellular domains directly recruit c-Src.
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Affiliation(s)
- W Cao
- Departments of Psychiatry and Behavioral Sciences, Pharmacology, and Medicine and the Howard Hughes Medical Institute, Duke University Medical Center, Durham, North Carolina 27710, USA
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129
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Yanagisawa T, Sato T, Yamada H, Sukegawa J, Nunoki K. Selectivity and potency of agonists for the three subtypes of cloned human beta-adrenoceptors expressed in Chinese hamster ovary cells. TOHOKU J EXP MED 2000; 192:181-93. [PMID: 11249148 DOI: 10.1620/tjem.192.181] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The selectivities, potencies and efficacies of beta3-adrenoceptor (beta3-AR) agonists on human three beta-AR subtypes expressed in Chinese hamster ovary (CHO) cells were investigated using radioligand binding assay and cyclic AMP (cAMP) accumulation assay. The three beta-AR subtypes showed the nature of G protein-coupled receptors with the constitutive activity. BRL37344, CL-316,243 and a newly synthesized beta3-AR agonist N-5984, 6-[2-(R)-[[2-(R)-(3-chlorophenyl)-2-hydroxyethyl]amino]propyl]-2,3-dihydro-1,4-benzodioxine-2-(R)-carboxylic acid, were compared for the potency and selectivity for the beta3-AR. In the radioligand binding assay, the affinity of N-5984 for beta3-ARs was 14, 70 and 220 times more potent than those of BRL37344, isoproterenol and CL-316,243, respectively. N-5984 had higher selectivity than BRL37344 for human beta3-ARs compared with either for beta1-ARs or beta2-ARs. N-5984 showed higher potency and intrinsic activity of cAMP production than BRL37344 in CHO cells expressing the beta3-ARs. CL-316,243 had almost no activity of cAMP production in CHO cells expressing any subtype of beta-ARs. These results indicate that N-5984 is the most potent and selective agonist for human beta3-ARs than any other agonists tested.
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Affiliation(s)
- T Yanagisawa
- Department of Physiology, Tohoku University School of Medicine, Sendai, Japan.
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130
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Abstract
As endocrinologists, we view better treatment as the goal of obesity research. The ideal obesity treatment would reduce body fat substantially, with preferential loss from the visceral compartment, and preserve lean tissue with a minimum of side effects. Obesity has been recognized as a chronic disease since 1985. Chronic diseases recognized before obesity may predict the future of obesity research. Initial treatments of chronic diseases commonly arise from empirical observations. These observations often stimulate basic research into the physiologic mechanisms responsible. Such cross-fertilization between the clinic and basic science is desirable and expected. As more is learned about the physiology of obesity, treatments can be expected to use more downstream mechanisms with less unwanted side effects, the reliance on surgical treatments can be expected to decline, and molecular approaches are likely to play an increasingly important role. With a better physiologic understanding of obesity, advanced clinical endpoints will become more important and molecular approaches are likely to play a more important role in discovery and treatment. Due to the availability of molecular approaches, obesity treatment is expected to advance faster than chronic disease research of the past.
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Affiliation(s)
- F L Greenway
- Outpatient Clinic, Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA.
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131
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Schnabel P, Maack C, Mies F, Tyroller S, Scheer A, Böhm M. Binding properties of beta-blockers at recombinant beta1-, beta2-, and beta3-adrenoceptors. J Cardiovasc Pharmacol 2000; 36:466-71. [PMID: 11026647 DOI: 10.1097/00005344-200010000-00008] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The human heart contains at least four distinct beta-adrenoceptor subtypes, three of which have been cloned. However, the binding properties of beta-blockers to the different beta-adrenoceptor subpopulations are not yet thoroughly characterized. Human beta1-, beta2- and beta3-adrenoceptors were expressed in COS-7 cells and [125I]iodocyanopindolol saturation binding, and competition experiments with commonly used beta-blockers were performed in the respective membrane preparations. Atenolol and metoprolol were about fivefold selective for beta1- versus beta2- and beta3-adrenoceptors. Bisoprolol was approximately 15-fold selective for beta1- versus beta2- and approximately 31-fold selective for beta1- versus beta3-adrenoceptors. Carvedilol was nonselective for any beta-adrenoceptor subtype. We conclude that the beta1-selectivities of atenolol, metoprolol, and bisoprolol are lower in COS cell membranes compared with previous investigations performed in native membranes. All beta-blockers investigated bind to beta3-adrenoceptors. Differential binding properties to beta3-adrenoceptors might imply different responses as to body weight, cardiac contractility, heart rate, and growth regulation. This might imply differential indications for the drugs investigated.
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MESH Headings
- Adrenergic beta-Antagonists/metabolism
- Animals
- Binding, Competitive/drug effects
- COS Cells
- DNA, Complementary/biosynthesis
- DNA, Complementary/genetics
- Humans
- In Vitro Techniques
- Iodocyanopindolol/metabolism
- Myocardium/metabolism
- Radioligand Assay
- Receptors, Adrenergic, beta-1/drug effects
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-2/drug effects
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Receptors, Adrenergic, beta-3/drug effects
- Receptors, Adrenergic, beta-3/genetics
- Receptors, Adrenergic, beta-3/metabolism
- Transfection
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Affiliation(s)
- P Schnabel
- Klinik III für Innere Medizin der Universität zu Köln, Cologne, Germany.
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132
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Mizuno K, Kanda Y, Kuroki Y, Watanabe Y. The stimulation of beta(3)-adrenoceptor causes phosphorylation of extracellular signal-regulated kinases 1 and 2 through a G(s)- but not G(i)-dependent pathway in 3T3-L1 adipocytes. Eur J Pharmacol 2000; 404:63-8. [PMID: 10980263 DOI: 10.1016/s0014-2999(00)00601-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The treatment of 3T3-L1 adipocytes with three beta(3)-adrenoceptor agonists, (+/-)-(R*, R*)-(4-[2-([2-(3-chlorophenyl)-2-hydroxyethyl]amino)propyl]phenoxy)ac etic acid (BRL37344), 4-[3-[(1, 1-dimethylethyl)amino]-2-hydroxypropoxy]-1, 3-dihydro-2H-benzimidazol-2-one (CGP12177) and [(7S)7-¿(2R)2-(3-chlorophenyl)-2-hydroxyethyl-amino¿-5,6,7, 8-tetrahydronapht-2-yl]ethyl oxyacetate, hydrochloride (SR58611) induces phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK1/2). The phosphorylations were not affected by pretreatment of the adipocytes with pertussis toxin, whereas the same treatment completely abolished lisophosphatidic acid-induced phosphorylation of ERK1/2, suggesting the role of pertussis toxin-insensitive G protein in the ERK1/2 phosphorylation by stimulation with the beta(3)-adrenoceptor agonists. The phosphorylation of ERK1/2 was mimicked by treating the adipocytes with cholera toxin, a direct activator of stimulatory G (G(s)) protein. In addition, the ERK1/2 phosphorylations by the beta(3)-adrenoceptor agonists were completely diminished by long-term treatment of the adipocytes with cholera toxin (100 ng/ml, 24 h), whereas that obtained with lisophosphatidic acid stimulation was not. Our findings strongly suggest that the three beta(3)-adrenoceptor agonists induce ERK1/2 phosphorylation in 3T3-L1 adipocytes through a G(s) protein-dependent cascade.
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Affiliation(s)
- K Mizuno
- Department of Pharmacology, National Defense Medical College, 3-2 Namiki, 359-8513, Tokorozawa, Japan
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133
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Abstract
Norepinephrine evoked a biphasic change in short-circuit current (Isc) across the proximal and distal colon of the rat. The (1) phase of the current response consisted of a transient increase, which was followed by a long-lasting decrease during the (2) phase. The (1) phase, which is assumed to represent Cl(-) secretion, was resistant against classical adrenoceptor antagonists, but was inhibited by the beta(3)-adrenoceptor antagonist 3-(2-ethylpenoxy)-1-[(1S-1,2,3, 4-tetrahydronaphth-1-ylaminol-(2S)-propranol oxalate (SR 59230A) in the proximal colon and by the non-selective beta-adrenoceptor antagonist bupranolol in both colonic segments. Vice versa, the increase in Isc was mimicked by the beta(3)-adrenoceptor agonist, (R*, R*)-(+/-)-4-[2-[(2-(3-chlorophenyl)-2-hydroxyethyl)amino]propyl]pheno xyacetic acid (BRL 37344). The (2) phase of the norepinephrine-induced Isc, which is assumed to represent K(+) secretion, was inhibited by yohimbine in the proximal colon, suggesting the mediation by alpha(2)-adrenoceptors, whereas in the distal colon, both alpha- and beta-adrenoceptors are involved, as shown by the sensitivity against, e.g. phentolamine and propranolol. These adrenoceptors seem to be located - at least in part - at extraepithelial sites because the (1) phase of the norepinephrine response was sensitive to indomethacin, and the (2) phase, both to indomethacin and tetrodotoxin.
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Affiliation(s)
- G Schultheiss
- Institut für Veterinär-Physiologie, Justus-Liebig-Universität Giessen, Frankfurter Str. 100, D-35392, Giessen, Germany.
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134
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Ferrarini PL, Mori C, Badawneh M, Calderone V, Greco R, Manera C, Martinelli A, Nieri P, Saccomanni G. Synthesis and beta-blocking activity of (R,S)-(E)-oximeethers of 2, 3-dihydro-1,8-naphthyridine and 2,3-dihydrothiopyrano[2, 3-b]pyridine:potential antihypertensive agents - part IX. Eur J Med Chem 2000; 35:815-26. [PMID: 11006483 DOI: 10.1016/s0223-5234(00)00173-2] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The synthesis of oximeethers of 2,3-dihydro-1,8-naphthyridine and 2, 3-dihydrothiopyrano[2,3-b]pyridine is described. These compounds exhibit a selective beta-blocking activity, with a selectivity towards beta(2)-receptors. Groups in the N(1) position giving rise to a considerable steric hindrance led to a higher beta(2)-blocking selectivity, whereas groups creating a moderate hindrance caused a weak but significant decrease in beta(2)-antagonist potency. Substitution of the N(1)-R group with a sulfur atom led to compounds possessing beta(1)-, beta(2)- and beta(3)-blocking properties. Compounds 9c(1) and 10a(1) showed a beta(3)-antagonist activity slightly lower than that of propranolol.
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Affiliation(s)
- P L Ferrarini
- Dipartimento di Scienze Farmaceutiche, Università di Pisa, via Bonanno 6, 56126, Pisa, Italy.
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135
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Nagatomo T, Koike K. Recent advances in structure, binding sites with ligands and pharmacological function of beta-adrenoceptors obtained by molecular biology and molecular modeling. Life Sci 2000; 66:2419-26. [PMID: 10894084 DOI: 10.1016/s0024-3205(00)80001-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The structure, binding sites interacting with ligands and the physiological functions of G-protein coupled beta-adrenoceptors (beta-ARs) are being elucidated by molecular biology and molecular modeling studies. The definition given amino acid sequences of beta-ARs in molecular biology and the analysis of three-dimensional and functional binding sites interacting with ligands by molecular modeling may be important for identifying other functional beta-ARs in various tissues and discovering new drugs. Thus, this review focuses on the interaction sites for receptor-ligand and roles of functional beta-ARs as studied by molecular biology and molecular modeling.
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Affiliation(s)
- T Nagatomo
- Department of Pharmacology, Niigata College of Pharmacy, Japan.
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136
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Anthony A, Sim R, Guillaume JL, Strosberg AD, Dhillon AP, Pounder RE, Wakefield AJ. Beta(beta)3-adrenergic receptors in human pancreatic islet and duodenal somatostatin neuroendocrine cells. Aliment Pharmacol Ther 2000; 14:579-85. [PMID: 10792121 DOI: 10.1046/j.1365-2036.2000.00722.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
BACKGROUND We previously localized beta3-adrenergic receptors immunohistochemically in human gastrointestinal smooth muscle and incidently found a population of human pancreatic islet cells and duodenal epithelial neuroendocrine cells that also expressed beta3-adrenergic receptors. AIM To identify the nature of the islet and duodenal cells that stained positive for beta3-adrenergic receptors. METHODS Paraffin sections of human pancreas and duodenum and Chinese hamster ovary cells transfected with the human beta3-adrenergic receptor were immuno-stained for beta3-adrenergic receptors using an affinity-purified rabbit polyclonal antibody (anti-P12) raised against a 15 amino acid sequence (P12) of the human receptor. Immunohistochemical staining for the receptor was carried out in the presence and absence of P12 peptide and both somatostatin 14 and 18 peptides. beta3-adrenergic receptor-stained sections were also double-immunostained with anti-insulin, -glucagon, -somatostatin and -pancreatic polypeptide antibodies. RESULTS A subpopulation of human pancreatic islet cells and duodenal epithelial cells expressed positive cytoplasmic beta3-adrenergic receptor immunostaining. Using distribution and double-staining techniques, these cells were found to be somatostatin-positive D cells but not A or B cells. The positive staining of D cells with anti-P12 antibody was inhibited by prior incubation of the antibody with P12 peptide but not somatostatin-14 or -28 peptides. Pancreatic vascular smooth muscle and duodenal vascular and non-vascular smooth muscle also stained with anti-P12 antibody. Transfected Chinese hamster ovary cells showed positive membrane staining. CONCLUSION We have identified a population of neuroendocrine cells in the human pancreas and duodenum that express beta3-adrenergic receptors. These cells appear to be somatostatin D cells.
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Affiliation(s)
- A Anthony
- University Department of Histopathology, Royal Free and University College Medical School, University College London, UK.
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137
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Matthys D, Derave W, Calders P, Pannier JL. Carbohydrate availability affects ammonemia during exercise after beta 2-adrenergic blockade. Med Sci Sports Exerc 2000; 32:940-5. [PMID: 10795784 DOI: 10.1097/00005768-200005000-00010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Beta-adrenergic blockade increases blood ammonia concentration during exercise. The purpose of this study was to assess the role of decreased carbohydrate availability in this process. METHODS Wistar rats (N = 47) were injected intravenously with a selective beta 2-adrenoceptor blocker (ICI 118,551), placebo, or beta 2-blocker + glucose 1 h before a treadmill exercise test. Blood samples were taken to measure the concentration of ammonia, glucose, lactic acid, free fatty acids (FFA), glycerol, branched-chain amino acids (BCAA), and muscle samples for determination of glycogen content. RESULTS Beta 2-adrenergic blockade shortened running time to exhaustion (23 +/- 4.3 min compared to 44 +/- 5.2 min with placebo), increased blood ammonia levels (146.7 +/- 16.21 micromol x L(-1) compared to 47.5 +/- 0.92 micromol x L(-1) with placebo) and prevented exercise-induced glycogen breakdown in soleus and gastrocnemius muscles. Pre-exercise supplementation of glucose during beta 2-blockade restored exercise-induced glycogen breakdown and reduced blood ammonia concentration during exercise (66.5 +/- 5.65 mmol x L(-1)) but did not improve exercise capacity (26 +/- 3.2 min) when compared with beta2-blockade alone. CONCLUSION The results suggest that the enhanced rise in blood ammonia concentration during exercise after beta-blockade is caused by impaired carbohydrate availability.
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Affiliation(s)
- D Matthys
- Department of Pediatric Cardiology, Institute of Kinesiology and Sport Sciences, University of Ghent, Belgium.
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138
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Berraondo B, Martínez JA. Free fatty acids are involved in the inverse relationship between hormone-sensitive lipase (HSL) activity and expression in adipose tissue after high-fat feeding or beta3-adrenergic stimulation. OBESITY RESEARCH 2000; 8:255-61. [PMID: 10832769 DOI: 10.1038/oby.2000.30] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
OBJECTIVE The hormone-sensitive lipase (HSL) is the rate-limiting enzyme in adipose tissue lipolysis. The aim of this experimental trial was to study the effects of a beta3-adrenergic agonist (Trecadrine) on plasma fatty acids, adipocyte HSL activity, and gene expression in control and cafeteria-induced obese animals. RESEARCH METHODS AND PROCEDURES Control and cafeteria-fed rats were treated with a placebo or Trecadrine during 35 days. Plasma fatty acids were measured by an enzymatic method, whereas HSL activity was assessed by using labeled triolein as substrate. Finally, HSL gene expression from white adipose tissue (WAT) was determined using a reverse transcription-polymerase chain reaction method. RESULTS Trecadrine administration reduced plasma fatty acids and HSL mRNA levels in abdominal WAT, whereas HSL activity was significantly higher in the Trecadrine-treated obese rats than in the obese nontreated rats. Also, abdominal WAT HSL activity significantly increased, whereas WAT HSL gene expression fell in control rats treated with beta3-adrenergic agonist as compared with control untreated animals. DISCUSSION In situations of fat accumulation (high-fat feeding) or lipid mobilization (beta3-adrenergic stimulation), changes in HSL activity and HSL gene expression seem to follow a trend related to plasma fatty acids levels, as indicated by the positive correlation (r = 0.39, p < 0.05) between HSL mRNA levels and plasma fatty acids, and the negative correlation (r = -0.38, p < 0.05) between plasma fatty acids and HSL activity. Furthermore, a highly negative correlation (r = -0.59, p < 0.001) between HSL activity and HSL mRNA expression was found, in which plasma-free fatty acids are apparently involved.
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Affiliation(s)
- B Berraondo
- Department of Physiology and Nutrition, University of Navarra, Pamplona, Spain
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139
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Mills S. Beta-adrenergic receptor subtypes mediating lipolysis in porcine adipocytes. Studies with BRL-37344, a putative beta3-adrenergic agonist. Comp Biochem Physiol C Toxicol Pharmacol 2000; 126:11-20. [PMID: 11048660 DOI: 10.1016/s0742-8413(00)00086-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The beta3-selective adrenergic receptor ligand BRL 37344 (BRL) was used to differentiate the presence and functional role of beta-adrenergic receptor (betaAR) subtypes in pig tissues. BRL did not stimulate adenylyl cyclase in membrane preparations or increase lipolysis from pig adipocytes. In contrast to some species, BRL appears to be a poor agonist for the pig betaAR and is not a useful betaAR ligand. Based on displacement of [3H]dihydroalprenolol binding, BRL exhibited a 100-fold selectivity for pig betaAR subtypes in adipose and skeletal muscle membranes. The high affinity site was proposed to be the beta2AR. When used as an antagonist, BRL blockade of the high affinity site did not interfere with isoproterenol-stimulated lipolysis but did inhibit adenylyl cyclase activation. Results indicate that the high affinity betaAR (betaAR) is not linked to lipolysis, possibly due to intracellular compartmentalization. Therefore, betaAR subtypes may have function-specific effects.
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Affiliation(s)
- S Mills
- Department of Animal Science, Purdue University, West Lafayette, IN 47906, USA.
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140
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Viard P, Macrez N, Coussin F, Morel JL, Mironneau J. Beta-3 adrenergic stimulation of L-type Ca(2+) channels in rat portal vein myocytes. Br J Pharmacol 2000; 129:1497-505. [PMID: 10742307 PMCID: PMC1571970 DOI: 10.1038/sj.bjp.0703187] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
1. The effects of beta(3)-adrenergic stimulation were studied on the L-type Ca(2+) channel in single myocytes from rat portal vein using the whole-cell mode of the patch-clamp technique. 2. Reverse transcription-polymerase chain reaction showed that beta(1)-, beta(2)- and beta(3)-adrenoceptor subtypes were expressed in rat portal vein myocytes. Application of both propranolol (a non-selective beta(1)- and beta(2)-adrenoceptor antagonist) and SR59230A (a beta(3)-adrenoceptor antagonist) were needed to inhibit the isoprenaline-induced increase in L-type Ca(2+) channel current. 3. L-type Ca(2+) channels were stimulated by CGP12177A (a beta(3)-adrenoceptor agonist with potent beta(1)- and beta(2)-adrenoceptor antagonist property) in a manner similar to that of isoprenaline. The CGP12177A-induced stimulation of Ca(2+) channel current was blocked by SR59230A, cyclic AMP-dependent protein kinase inhibitors, H-89 and Rp 8-Br-cyclic AMPs, but was unaffected by protein kinase C inhibitors, GF109203X and 19-31 peptide. This stimulation was mimicked by forskolin and 8-Br-cyclic AMP. In the presence of okadaic acid (a phosphatase inhibitor), the beta(3)-adrenoceptor-induced stimulation was maintained after withdrawal of the agonist. 4. The beta(3)-adrenoceptor stimulation of L-type Ca(2+) channels was blocked by a pretreatment with cholera toxin and by the intracellular application of an anti-Galpha(s) antibody. This stimulation was unaffected by intracellular infusion of an anti-Gbeta(com) antibody and a betaARK(1) peptide. 5. These results show that activation of beta(3)-adrenoceptors stimulates L-type Ca(2+) channels in vascular myocytes through a Galpha(s)-induced stimulation of the cyclic AMP/protein kinase A pathway and the subsequent phosphorylation of the channels.
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MESH Headings
- 1-Propanol/pharmacology
- 8-Bromo Cyclic Adenosine Monophosphate/pharmacology
- Adrenergic beta-Agonists/pharmacology
- Adrenergic beta-Antagonists/pharmacology
- Animals
- Barium/pharmacology
- Calcium Channels, L-Type/drug effects
- Calcium Channels, L-Type/metabolism
- Cells, Cultured
- Cholera Toxin/pharmacology
- Colforsin/pharmacology
- Dose-Response Relationship, Drug
- Electric Stimulation
- Isoproterenol/pharmacology
- Isoquinolines/pharmacology
- Membrane Potentials/drug effects
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/physiology
- Phorbol 12,13-Dibutyrate/pharmacology
- Portal Vein/cytology
- Portal Vein/drug effects
- Portal Vein/physiology
- Propanolamines/pharmacology
- RNA, Messenger/genetics
- Rats
- Receptors, Adrenergic, beta/drug effects
- Receptors, Adrenergic, beta/genetics
- Receptors, Adrenergic, beta/physiology
- Receptors, Adrenergic, beta-3
- Reverse Transcriptase Polymerase Chain Reaction
- Signal Transduction
- Sulfonamides
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Affiliation(s)
- Patricia Viard
- Laboratoire de Physiologie Cellulaire et Pharmacologie Moléculaire, CNRS UMR 5017, Université de Bordeaux II, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
| | - Nathalie Macrez
- Laboratoire de Physiologie Cellulaire et Pharmacologie Moléculaire, CNRS UMR 5017, Université de Bordeaux II, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
| | - Frédéric Coussin
- Laboratoire de Physiologie Cellulaire et Pharmacologie Moléculaire, CNRS UMR 5017, Université de Bordeaux II, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
| | - Jean-Luc Morel
- Laboratoire de Physiologie Cellulaire et Pharmacologie Moléculaire, CNRS UMR 5017, Université de Bordeaux II, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
| | - Jean Mironneau
- Laboratoire de Physiologie Cellulaire et Pharmacologie Moléculaire, CNRS UMR 5017, Université de Bordeaux II, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
- Author for correspondence:
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141
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Abstract
Consolidation of a labile memory which would not normally be stored can be achieved by intracerebral administration of noradrenaline. In a series of experiments using discriminated, one trial passive avoidance learning with the day-old chick, the effect of noradrenaline has been shown to be due to actions at different subtypes of adrenoceptors. The effect of noradrenaline is dose-dependent, with a moderate dose producing memory consolidation. However, higher doses of noradrenaline (0.3-10 nmol/hemisphere) prevent consolidation, an effect not seen with isoprenaline suggesting that these doses stimulate alpha-adrenoceptors. The promotion of memory consolidation by noradrenaline or isoprenaline at low doses was attributable to beta3-adrenoceptors and at medium doses to beta2-adrenoceptors. At higher doses of noradrenaline, there was alpha1-adrenoceptor-mediated inhibition of memory consolidation. Consolidation can also be achieved by administration of either beta2- or beta3-adrenoceptor agonists at specific times after training. Although these two adrenoceptors both promoted memory consolidation, there was a differential action on the stages of memory formation. The dose-response curve to the beta3- and the beta2-agonists was shifted by the appropriate antagonist but not by the antagonist at the other beta-adrenoceptor. Although beta1-adrenoceptors are present in chick brain, they do not seem to have a role in memory formation. These results explain why noradrenaline, acting at different adrenoceptors, can have different effects on memory formation with memory being either consolidated or inhibited depending on the dose. The findings also demonstrate a role in memory formation for beta3-adrenoceptors found in the brain. Agonists acting specifically at beta2- or beta3-adrenoceptors may be of value in diseases involving cognitive impairment.
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Affiliation(s)
- M E Gibbs
- Department of Psychology, Monash University, Clayton, Australia
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142
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Love JA, Szebeni K, Smith TG. Role of adrenergic receptors in veratridine-stimulated amylase secretion from rabbit pancreatic lobules. Pancreas 2000; 20:177-83. [PMID: 10707934 DOI: 10.1097/00006676-200003000-00011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
Sympathetic inhibition of pancreatic enzyme secretion has been attributed to vasoconstriction and direct inhibition of acinar cells. We observed both adrenergic inhibition and facilitation of cholinergic transmission in rabbit pancreatic ganglia, which innervate acini. Here we used pancreatic lobules to determine whether adrenergic receptors also regulate synaptic transmission between pancreatic nerves and acini. Stimulation of pancreatic nerve terminals with veratridine (Ver), an activator of voltage-dependent Na+ channels, resulted in a 102% increase in amylase secretion, which was unaffected by alpha and beta receptor antagonists but inhibited 65% by atropine. At a concentration of 10 microM, norepinephrine inhibited (38%) and epinephrine potentiated (40%) Ver-stimulated secretion. At the same concentration, the alpha2 agonist clonidine (Clon) inhibited (39%), whereas the nonselective beta agonist isoproterenol (Iso) and the selective beta3 agonist BRL 37344 potentiated (71 and 67%, respectively) nerve-stimulated secretion. The effects of Clon and Iso and BRL 37344 were antagonized by yohimbine and propranolol, respectively. Phenylephrine, dobutamine, and terbutaline had no effect. Neither basal, bethanechol-stimulated, nor noncholinergic nerve-stimulated secretion was significantly altered by Clon or Iso. Thus, cholinergic nerve terminals innervating pancreatic acini exhibit both inhibitory alpha2 and atypical facilitatory beta adrenergic receptors. The apparent lack of adrenergic innervation suggests that adrenergic receptors on the nerve terminals of cholinergic pancreatic neurons are under hormonal control by circulating catecholamines. These results provide further evidence that intrinsic pancreatic neurons, which supply most, if not all, of the cholinergic innervation of acini, are important sites of sympathetic regulation of pancreatic exocrine secretion.
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Affiliation(s)
- J A Love
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson 39216-4505, USA.
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143
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Abstract
Although the rapid increase in the prevalence of obesity in many countries suggests that environmental factors (mainly overeating and physical inactivity) play the most important role in the development of overweight, it is very likely that genetic factors also contribute. It appears that one major gene in combination with one or several minor genes constitute the genetic components behind excess accumulation of body fat in most obese individuals. However, monogenic obesity has been described in a few families due to changes in leptin, leptin receptor, prohormone convertase, pro-opiomelanocortin or melanocortin-4 receptor. None of the monogenic variants is of great importance for common human obesity; the latter genes are unknown so far. Results from genomic scans suggest that major obesity genes are located on chromosomes 2, 10, 11 and 20. Studies of candidate genes indicate that the minor obesity genes control important functions of adipose tissue, and that structural variance in these genes may alter adipose tissue function in a way that promotes obesity. Such genes are beta 2- and beta 3-adrenoceptors, hormone-sensitive lipase, tumour necrosis factor alpha, uncoupling protein-1, low-density lipoprotein receptor, and peroxisome proliferator activator receptor gamma-2. Some of these genes may promote obesity by gene-gene interactions (for example beta 3-adrenoceptors and uncoupling protein-1) or gene-environment interactions (for example beta 2-adrenoceptors and physical activity). Some are important for obesity only among women (for example beta 2- and beta 3-adrenoceptors, low-density lipoprotein receptor and tumour necrosis factor alpha). Few 'non-adipose' genes have so far shown a firm association to common human obesity, which could suggest that the important genes for the development of excess body fat also control adipose tissue function.
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Affiliation(s)
- P Arner
- Karolinska Institute, Department of Medicine, CME, Huddinge Hospital, Stockholm, Sweden.
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144
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Berraondo B, Marti A, Duncan JS, Trayhurn P, Martínez JA. Up-regulation of muscle UCP2 gene expression by a new beta3-adrenoceptor agonist, trecadrine, in obese (cafeteria) rodents, but down-regulation in lean animals. Int J Obes (Lond) 2000; 24:156-63. [PMID: 10702765 DOI: 10.1038/sj.ijo.0801097] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE The anti-obesity properties of a new beta3-adrenergic agonist (Trecadrine) were examined in a diet-induced obesity model, including the effects on OB and uncoupling protein (UCP-1 and -2) gene expression. MEASUREMENTS Control rats and cafeteria-fed rats were treated with placebo or Trecadrine for 35 days. Leptin and UCP (1 and 2) mRNA levels were determined by reverse transcription-polymerase chain reaction (RT-PCR) methodology in adipose tissue and gastrocnemius muscle. RESULTS Animals fed a cafeteria diet increased body weight, fat content, white adipose tissue (WAT), brown adipose tissue (BAT) weights and oxygen consumption in relation to lean controls. A rise in plasma leptin, WAT OB gene expression as well as circulating free fatty acids levels was found in obese rats as compared with lean controls. Trecadrine administration to cafeteria-fed animals decreased fat content, WAT weight, circulating leptin and fatty acids concentrations, and WAT OB gene expression, reaching comparable values to lean controls, while WAT O2 consumption was increased in these animals. Also, an increase in BAT UCP1 mRNA levels was found through a two-way analysis of variance in control and obese animals after Trecadrine administration. Gastrocnemius muscle UCP2 gene expression was reduced in lean Trecadrine-treated and diet-induced obese animals as compared to controls, while an increase was found in cafeteria-fed animals after Trecadrine administration. A negative correlation between WAT O2 consumption and UCP2 expression was found in control animals, but not in the cafeteria-fed groups, suggesting a differential response to the beta3-adrenergic compound in lean and obese animals, which is in agreement with the reported statistical interactions between obesity and Trecadrine administration found for WAT O2 consumption and muscle UCP2 expression, as well as for plasma leptin and WAT leptin expression. CONCLUSION The new beta3-adrenergic agonist, Trecadrine, decreases fat content and increases gastrocnemius muscle UCP2 gene expression in a diet-induced obesity model. This sheds additional light on the action mechanism of compounds with affinity for beta3-adrenoceptors and other potential anti-obesity agents.
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Affiliation(s)
- B Berraondo
- Department of Physiology and Nutrition, University of Navarra, 31008 Pamplona (Navarra), Spain
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145
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Weyer C, de Souza CJ. Development of ?3-adrenoceptor agonists as antiobesity and antidiabetes drugs in humans: Current status and future prospects. Drug Dev Res 2000. [DOI: 10.1002/1098-2299(200010)51:2<80::aid-ddr4>3.0.co;2-e] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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146
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Pugh E, Lamb T. Chapter 5 Phototransduction in vertebrate rods and cones: Molecular mechanisms of amplification, recovery and light adaptation. HANDBOOK OF BIOLOGICAL PHYSICS 2000. [DOI: 10.1016/s1383-8121(00)80008-1] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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147
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Affiliation(s)
- G A Bray
- Louisiana State University, Pennington Biomedical Research Center, Baton Rouge 70808-4124, USA
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148
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García-Rubi E, Calles-Escandón J. Insulin resistance and type 2 diabetes mellitus: its relationship with the beta 3-adrenergic receptor. Arch Med Res 1999; 30:459-64. [PMID: 10714358 DOI: 10.1016/s0188-4409(99)00077-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
The beta 3 subtype of adrenaline and noradrenaline receptors has been extensively characterized at structural and functional levels. Ligand binding and adenyl cyclase activation studies have helped to define their unique beta-adrenergic profile. Humans, other larger mammals, and rodents share most of the characteristic beta 3-adrenergic receptor properties, although obvious species-specific differences have been identified. Most studies in animal models have shown a distinct beta 3-adrenergic receptor activity that results in an increase in energy expenditure, decrease of fat mass (especially of intra-abdominal fat), and increased glucose disposal efficiency. It is of interest that mild weight increase was shown to develop in female but not male mice, in whom the beta 3-adrenergic receptor gene was disrupted. Recently, the incidence of a naturally occurring variant of the human beta 3-adrenergic receptor was shown to correlate with hereditary obesity in Pima Indians and Japanese individuals. In Western obese patients, this phenotype increased the capacity to gain weight and develop type 2 diabetes mellitus. Studies of humans with the Trp64Arg variant have shown controversial results. Many studies have failed to show any effect in heterozygous male subjects, and only modest effects in homozygous male subjects. In women, several studies have shown modest-to-significant effects regarding weight gain, intra-abdominal fat, and decreased insulin sensitivity in heterozygous and homozygous women. Other studies have failed to show any effect in heterozygous females. Disruptions in the activity of the beta 3-adrenergic receptor in the homozygous male and the heterozygous or homozygous female appear to have a profound effect in animal models, but a limited consequence in human physiology. Association with obesity or diabetes in humans is still controversial. This difference between animal and human models may be explained by the different quantity and distribution of metabolically active brown adipose tissue in the two.
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MESH Headings
- Animals
- Diabetes Mellitus, Type 2/genetics
- Diabetes Mellitus, Type 2/metabolism
- Humans
- Insulin Resistance/genetics
- Receptors, Adrenergic, beta/genetics
- Receptors, Adrenergic, beta/metabolism
- Receptors, Adrenergic, beta/physiology
- Receptors, Adrenergic, beta-3
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Affiliation(s)
- E García-Rubi
- Endocrinology, Diabetes, and Metabolism Unit, University of Vermont College of Medicine, Burlington 05405-0068, USA.
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Zulet MA, Berraondo B, Milagro FI, Martínez JA. Hypolipidemic properties of a diphenyl-methylen-ethylamine derivative with affinity for beta 3-adrenoceptors in a model of hypercholesterolemia. FARMACO (SOCIETA CHIMICA ITALIANA : 1989) 1999; 54:710-2. [PMID: 10575741 DOI: 10.1016/s0014-827x(99)00087-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
beta 3-Adrenergic agonists have been proposed as potential new drugs for the treatment of diabetes and/or obesity therapy, because of the hypoglycemic and lipolytic effects found with some of these compounds. Moreover, their application in other therapeutic areas such as hypercholesterolemia and atherosclerosis has been suggested. This experimental trial was conducted to assess the effects of Trecadrine, a new molecule with affinity for beta 3-adrenoceptors, on a model of hypercholesterolemia in rats, and also to explore a possible beneficial role of these agents in lipid disturbances therapy. The results indicated a marked reduction in serum triglyceride levels (-40%; P < 0.01) and lipoprotein lipase activity in white fat (-49%, P < 0.001) of hypercholesterolemic rats treated with Trecadrine for 16 days as compared with hypercholesterolemic non-treated rats. Moreover, Trecadrine produced a significant increase in the oxygen consumption in brown adipose tissue (+154%, P < 0.01). In relation to cholesterolemia, an improvement in total cholesterol (-20%) and total/HDL-cholesterol ratio (-25%) in serum was noted in the animals receiving the pharmacological treatment. In conclusion, the results of this trial support that Trecadrine administration may have a therapeutic potential in disorders associated with hypertriglyceridemia such as obesity and some types of hyperlipidaemias.
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Affiliation(s)
- M A Zulet
- Department of Physiology and Nutrition, University of Navarra, Pamplona, Spain
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Christiansen C, Poulsen P, Beck-Nielsen H. The Trp64Arg mutation of the adrenergic beta-3 receptor gene impairs insulin secretion: a twin study. Diabet Med 1999; 16:835-40. [PMID: 10547210 DOI: 10.1046/j.1464-5491.1999.00130.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS The physiological role of the adrenergic beta-3 receptor is poorly understood in man but the Trp64Arg mutation of the receptor gene has been related to the insulin resistance syndrome, an earlier onset of diabetes and rapid weight gain. This study set out to examine the effects of the mutation on glycaemic responses after an oral glucose tolerance test. METHODS A standard oral glucose tolerance test (75 g glucose) was performed in 196 dizygotic twins. Serum insulin and glucose responses were measured at 0, 30 and 120 min. RESULTS In the twins discordant for the mutation (21 pairs), no effects of the mutation were found on the plasma glucose responses. The insulin response given as incremental area under curve (iAUC) (median 13.8 (25-75th percentile 9.3-21.0) vs. 23.3 (14.2-29.2) mmol x l(-1) x min, P<0.021) and the insulinogenic index ((insulin30min - insulin0min)/ (glucose30min - glucose0min)), a measure of the insulin secretory capacity (44 (34-58) vs. 75 (42-124), P<0.006), were considerably lower in the variant type. The results were confirmed when using non-paired statistics on all subjects. CONCLUSION It was concluded that the adrenergic beta-3 receptor, in addition to its already known effects, may be involved in the regulation of insulin secretion and that patients with the Trp64Arg mutation present an impaired insulin secretion.
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