Advertisement

Human fat cell beta-adrenergic receptors: beta-agonist-dependent lipolytic responses and characterization of beta-adrenergic binding sites on human fat cell membranes with highly selective beta 1-antagonists.

Open AccessPublished:May 01, 1988DOI:https://doi.org/10.1016/S0022-2275(20)38502-3
      This paper is only available as a PDF. To read, Please Download here.
      Beta-adrenergic receptors were characterized in human fat cell membranes using 125I-labeled cyanopindolol (125I-labeled CYP) and highly selective beta 1-antagonists. The iodinated radioligand bound saturably and specifically to a single class of high affinity binding sites. The number of binding sites determined with 125I-labeled CYP closely agreed with that determined with two other tritiated radioligands: [3H]dihydroalprenolol and [3H]CGP-12,177. Since 125I-labeled CYP does not discriminate between beta 1- and beta 2-adrenoceptors, the densities of the two receptor subtypes were determined from the competition curves of 125I-labeled CYP by highly selective beta 1-antagonists (bisoprolol, ICI-89,406, CGP-20,712A, and LK-204,545). Moreover, in order to enable correlation with binding data, the regulation of adenylate cyclase activity and of lipolysis was tested with various beta-agonist and antagonist compounds. The results obtained on fat cell membranes from abdominal subcutaneous adipose tissue demonstrated the following. 1) 125I-labeled CYP represents a valuable tool for the quantification and the delineation of beta-receptor subtypes. 2) The presence of sodium ions in binding buffers causes a modification of the affinity of beta-sites for some beta-antagonists. 3) The human fat cell beta adrenergic receptor population defined by nonselective radioligands is composed of two subtypes that can be interpreted in terms of classic beta 1- and beta 2-adrenergic receptor subtypes as assessed by competition studies with highly selective antagonists; beta 2-sites are predominant (60-70% of 125I-labeled CYP sites) in the adipocytes of slightly overweight women. 4) Results support the idea that beta 1- as well as beta 2-adrenergic receptors are coupled with adenylate cyclase and involved in the induction of lipolysis. 5) The results focus on the interest in some beta 2-agonist drugs (zinterol, clenbuterol) as partial inductors of lipolysis, with the lipolytic efficacies of these compounds being well correlated with their efficacies at 125I-labeled CYP sites.

      REFERENCES

        • Harms H.H.
        • De Vente J.
        • Zaagsma J.
        Betaadrenoceptor blocking agents and lipolysis.
        Br. J Clin. Pharmacol. 1982; 13: 181-186
        • Fain J.N.
        • Garcia-Sainz J.A.
        Adrenergic regulation of adipocyte metabolism.
        J. Lipid Res. 1983; 24: 945-966
        • Lafontan M.
        • Berlan M.
        • Carpene C.
        Fat cell adrenoceptors: interand intraspecific differences and hormone regulation.
        Int. J. Obes. 1985; 9: 117-127
        • Mauriège P.
        • Galitzky J.
        • Berlan M.
        • Lafontan M.
        Heterogeneous distribution of alpha2-adrenoceptor binding sites in human fat cells from various fat deposits: functional consequences.
        Eur. J. Clin. Invest. 1987; 17: 156-165
        • Bojanic D
        • Nahorski S.R.
        Identification and subclassification of rat adipocyte beta-adrenoceptors using (+)[125I]cyanopindolol.
        Eur. J. Pharmacol. 1983; 93: 235-243
        • Wilson C.
        • Wilson S.
        • Piercy U.
        • Sennitt M.V.
        • Broadley K.J.
        The rat lipolytic β-adrenoceptor: studies using a novel β-adrenoceptor agonist.
        Eur. J. Pharmacol. 1984; 100: 309-319
        • Grassby P.F.
        • Arch J.R.S.
        • Wilson C.
        • Broadley K.J.
        Beta-adrenoceptor sensitivity of brown and white adipocytes after chronic pretreatment of rats with reserpine.
        Biochem. Pharmacol. 1987; 36: 155-162
        • Mersmann H.J.
        Specificity of β-adrenergic control of lipolysis in swine adipose tissue.
        Comp. Biochem. Physiol. 1984; 77C: 39-42
        • Burns T.W.
        • Langley P.E.
        • Terry B.E.
        • Bylund D.B.
        • Hoffman B.B.
        • Tharp M.D.
        • Lefkowitz R.J.
        • Garcia- Sainz J.A.
        • Fain J.N.
        Pharmacological characterization of adrenergic receptors in human adipocytes.
        J. Clin. Invest. 1981; 67: 467-475
        • Engfeldt P.
        • Arner P.
        • Wahrenberg H.
        • Ostman J.
        An assay for beta-adrenergic receptors in isolated human fat cells.
        J. Lipid Res. 1982; 23: 715-719
        • Richelsen B.
        Increased alpha2- but similar betaadrenergic receptor activities in subcutaneous gluteal adipocytes from females compared with males.
        Eur. J. Clin. Invest. 1986; 16: 302-309
        • Lacasa D.
        • Mauriège P.
        • Lafontan M.
        • Berlan M.
        • Giudicelli Y.
        A reliable assay for beta-adrenoceptors in intact isolated human fat cells with a hydrophilic radioligand, [3H]CGP-12177.
        J. Lipid Res. 1986; 27: 368-376
        • Hoyer D
        • Engel G.
        • Berthold R.
        Binding characteristics of (+)-, (±)- and (-)- [125Iodo]cyanopindolol to guinea pig left ventricle membranes.
        Naunyn Schmiedeberg's Arch. Pharmacol. 1982; 318: 319-329
        • Neve K.A.
        • Barrett D.A.
        • Molinoff P.B.
        Selective regulation of beta-1 and beta-2 adrenergic receptors by atypical agonists.
        J. Pharmacol. Exp. Ther. 1985; 235: 657-664
        • Levin B.E.
        • Sullivan A.C.
        Beta-1 receptor is the predominant beta-adrenoceptor on rat brown adipose tissue.
        J. Pharmacol. Exp. Ther. 1986; 236: 681-688
        • Milavec-Krizman M.
        • Evenou J-P.
        • Wagner H.
        • Berthold R.
        • Stoll A.P.
        Characterization of beta-adrenoceptor subtypes in rat kidney with new highly selective beta-1 blockers and their role in renin release.
        Biochem. Pharmacol. 1985; 34: 3951-3957
        • Dooley D.J.
        • Bittiger H.
        • Reymann N.C.
        CGP- 20, 712A: a useful tool for quantitating β1- and β2-adrenoceptors.
        Eur. J. Pharmacol. 1986; 130: 137-139
        • Kaumann A.J.
        • Lemoine H.
        Direct labelling of myocardial β1-adrenoceptors. Comparison of binding affinity of (-)[3H]bisoprolol with its blocking potency.
        Naunyn Schmiedeberg's Arch. Pharmacol. 1985; 331: 27-39
        • Rodbell M.
        Metabolism of isolated fat cells. 1. Effects of hormones on glucose metabolism and lipolysis.
        J. Biol. Chem. 1964; 239: 375-380
        • Lafontan M.
        • Berlan M.
        • Villeneuve A.
        Preponderance of alpha2- over beta1-adrenergic receptor sites in human fat cells is not predictive of the lipolytic effect of physiological catecholamines.
        J. Lipid Res. 1983; 24: 429-440
        • Lowry O.H.
        • Rosebrough N.J.
        • Farr A.L.
        • Randall R.J.
        Protein measurement with the Folin phenol reagent.
        J. Biol. Chem. 1951; 193: 265-275
        • Salomon Y.
        • Londos C.
        • Rodbell M.
        A highly sensitive adenylate cyclase assay.
        Anal. Biochem. 1974; 58: 541-548
        • Munson P.J.
        • Rodbard D
        LIGAND: a versatile computerized approach for characterization of ligand binding systems.
        Anal. Biochem. 1980; 107: 220-239
        • Engle G.
        • Hoyer D.
        • Berthold R.
        • Wagner H.
        (±)[125Iodo]cyanopindolol, a new ligand for beta-adrenoceptors: identification and quantitation of subclasses of beta-adrenoceptors in guinea pig.
        Naunyn Schmiedeberg's Arch. Pharmacol. 1981; 317: 277-285
        • Berlan M.
        • Lafontan M.
        Evidence that epinephrine acts preferentially as an antilipolytic agent in abdominal human subcutaneous fat cells: assessment by analysis of betaand alpha2-adrenoceptors properties.
        Eur. J. Clin. Invest. 1985; 15: 341-348
        • Stock M.J.
        • Rothwell N.J.
        Effects of betaadrenergic agonists on metabolism and body composition.
        in: Buttery P.J. Haynes N.B. Lindsay D.B. Growth and Manipulation of Animal Growth. Butterworths, London1986: 249-257
        • Kather H.
        • Geiger M.
        Adrenaline-sensitive adenylate cyclase of human fat cell ghosts: properties and hormone sensitivity.
        Eur. J. Clin. Invest. 1977; 7: 363-371
        • Katz M.S.
        • Partilla J.S.
        • Pineyro M.A.
        • Gregerman R.I.
        Essential role of GTP in epinephrine stimulation of human fat cell adenylate cyclase.
        J. Lipid Res. 1981; 22: 113-121
        • Zaagsma J.
        • Meems L.
        • Boorsma M.
        Betaadrenoceptor studies. 4. Influence of albumin on in vitro β- adrenoceptor blocking and antiarrhythmic properties of propranolol, pindolol, practolol and metoprolol.
        Naunyn Schmiedeberg's Arch. Pharmacol. 1977; 298: 29-36
        • Dax E.M.
        • Partilla J.S.
        • Gregerman R.I.
        The (-)[3H]dihydroalprenolol binding to rat adipocyte membranes: an explanation of curvilinear Scatchard plots and implications for quantitation of β-adrenergic sites.
        J. Lipid Res. 1982; 23: 1001-1008
        • Dax E.M.
        • Partilla J.S.
        Adrenergic ligand liposolubility in membranes: direct assessment in a β- adrenergic binding system.
        Mol. Pharmacol. 1982; 22: 5-7
        • Homburger V.
        • Lucas M.
        • Rosenbaum E.
        • Vassent G.
        • Bockaert J.
        Presence of both betaland beta2-adrenergic receptors in a single cell type.
        Mol. Pharmacol. 1981; 20: 463-469
        • Robberecht P.
        • Delhaye M.
        • Taton G.
        • De Neef P.
        • Walbroeck M.
        • De Smet J.M.
        • Leclerc J-L.
        • Chatelain P.
        • Christophe J.
        The human heart beta-adrenergic receptors. 1. Heterogeneity of the binding sites: presence of 50% betaland 50% beta2-adrenergic receptors.
        Mol. Pharmacol. 1983; 24: 169-173
        • Liang B.T.
        • Molinoff P.B.
        Beta-adrenergic receptor subtypes in the atria: evidence for close coupling of betaland beta2-adrenergic receptors to adenylate cyclase.
        J. Pharmacol. Exp. Ther. 1986; 238: 886-892
        • Ariens E.J.
        • Simonis A.M.
        Physiological and pharmacological aspects of adrenergic receptor classification.
        Biochem. Pharmacol. 1983; 32: 1539-1545
        • Stiles G.L.
        • Taylor S.
        • Lefkowitz R.J.
        Human cardiac beta-adrenergic receptors: subtype heterogeneity delineated by direct radioligand binding.
        Life Sci. 1983; 33: 467-473
        • McPherson G.A.
        • Molenaar P.
        • Malta E.
        • Raper C.
        Influence of assay buffer on dissociation constants of drugs at β-adrenoceptor subtypes.
        Eur. J. Pharmacol. 1985; 119: 93-100
        • Ijzerman A.P.
        • Dorlas R.
        • Aué G.H.J.
        • Bultsma T.
        • Timmerman H.
        Factors controlling β1-adrenoceptor affinity and selectivity.
        Biochem. Pharmacol. 1985; 34: 2883-2890
        • Heidenreich K.A.
        • Wieland G.A.
        • Molinoff P.B.
        Characterization of radiolabeled agonist binding to β-adrenergic receptors in mammalian tissues.
        J. Cyclic Nucleotide Res. 1980; 6: 217-230
        • U'Prichard D.C.
        • Byland D.B.
        • Snyder S.H.
        (±)[3H]Epinephrine and (-)[3H]dihydroalprenolol binding to betaland beta2-noradrenergic receptors in brain, heart and lung membranes.
        J. Biol. Chem. 1978; 253: 5090-5102
        • Minuth M.
        • Jakobs K.H.
        Sodium regulation of agonist and antagonist binding to β-adrenoceptors in intact and Ns-deficient membranes.
        Naunyn Schmiedeberg's Arch. Pharmacol. 1986; 333: 124-129
        • Lands A.M.
        • Arnold A.
        • McAuliff J.P.
        • Luduena P.
        • Brown I.G.
        Differentiation of receptor systems activated by sympathomimetic amines.
        Nature. 1967; 214: 597-598
        • Goldberg R.
        • Van As M.
        • Joffe B.I.
        • Krut L.
        • Bersohn I.
        • Seffel H.C.
        Metabolic responses to selective β- adrenergic stimulation in man.
        Postgrad. Med. 1975; 51: 53-58
        • Day J.L.
        • Simpson C.L.
        • Metcalfe J.
        • Page R.L.
        Metabolic consequences of atenolol and propranolol in treatment of essential hypertension.
        Br. Med. J. 1979; 1: 77-80
        • Franz I.W.
        • Lohmann F.W.
        • Koch G.
        • Quabbe H.J.
        Aspects of hormonal regulation of lipolysis during exercise: effects of chronic beta-receptor blockade.
        Int. J. Sports Med. 1983; 4: 14-20
        • Nilsson A.
        • Hansson B-G.
        • Hökfelt B.
        Effect of metoprolol on blood glycerol, free fatty acids, triglycerides and glucose in relation to plasma catecholamines in hypertensive patients at rest and following submaximal work.
        Eur. J. Clin. Pharmacol. 1978; 13: 5-8
        • Wahrenberg H.
        • Arner P.
        • Engfeldt P.
        • Haglund K.
        • Rössner S.
        • Ostman J.
        Long-term β1-selective adrenergic blockade and adrenergic receptors in human subcutaneous adipocytes.
        Acta. Med. Scand. 1985; 217: 539-546