Regional differences of β1- and β2-adrenoceptor-mediated functions in feline heart

A β2-adrenoceptor-mediated positive inotropic effect possibly unrelated to cyclic AMP
  • H. Lemoine
  • A. J. Kaumann
Article

Summary

The effects of (−)-adrenaline and (−)-noradrenaline were studied on isolated preparations of kitten heart. To define the contribution of β1-adrenoceptors (β1AR) and β2-adrenoceptors (β2AR) we used as tools the highly β1AR-selective antagonist CGP 20,712 A and non-linear analysis of antagonism. The β2AR-mediated responses to the catecholamines, disclosed by CGP 20,712 A, were verified by blockade with the β2AR-selective ICI 118,551. The relative density and contribution of β1AR and β2AR to (−)-adrenaline- and (−)-noradrenaline-induced adenylyl cyclase stimulation was also estimated in right ventricular membranes.

  1. 1.

    In the sinoatrial pacemaker (−)-adrenaline caused positive chronotropic effects through both β1AR and β2AR while (−)-noradrenaline does so predominantly through β1AR. During β1AR blockade (−)-adrenaline did cause the same maximum effects through β2AR as (−)-noradrenaline did through β1AR.

     
  2. 2.

    In left atria (−)-adrenaline caused positive inotropic effects predominantly through β1AR. CGP 20,712A also uncovered a β2AR component at high (−)-adrenaline concentrations comprising one third of the maximum β1AR-mediated response.

     
  3. 3.

    Receptor binding assays revealed that 80% of right ventricular βAR wereβ1AR and 20% β2AR. Consistent with this finding, around 80% of the adenylyl cyclase stimulation by both (−)-noradrenaline and (−)-adrenaline was mediated through β1AR, around 20% through β2AR. The positive inotropic effects of (−)-noradrenaline appeared to be nearly exclusively mediated through β1AR in right ventricular papillary muscles. were quite variable with regard to β1AR and β2AR in right ventricular papillary muscles. Although β1AR-mediated effects are predominant in many muscles with only a small contribution of β2AR, in some muscles β2AR mediated around 50% of the maximum effect elicited through β1AR. In 3 out of 17 muscles β2AR mediated the same maximum effect of (−)-adrenaline as β1AR.

     
  4. 5.

    On occasion, we found marked βAR heterogeneity amongst two muscles from the same right ventricle. One muscle only exhibited β1AR-mediated effects of (−)-adrenaline whereas in the other muscle maximal effects could be elicited through β2AR.

     
  5. 6.

    CGP 20,712 A had the same affinity for β1AR (pKB = 9.6) and β2AR (pKB = 5.4) in all 3 heart regions studied, suggesting identical affinities of the corresponding receptors. The pronounced tissue differences in the function of β1AR and β2AR appear therefore due to marked differences in receptor density or receptor coupling.

     
  6. 7.

    Surprisingly, pronounced β2AR-mediated inotropic effects of (−)-adrenaline in right ventricular papillary muscles showed prolonged relaxation times; furthermore, the time to peak force was not shortened. These observations are inconsistent with an involvement of cyclic AMP. In contrast, β1AR-mediated effects of both (−)-noradrenaline and (−)-adrenaline shortened time to peak force, as expected from an involvement of cyclic AMP.

     
  7. 8.

    We suggest that feline ventricular β2AR mediate an inotropic effect of (−)-adrenaline that does not involve cyclic AMP. This effect may be due to the direct opening of calcium channels by Gs protein reported by Yatani et al. (1987).

     

Key words

Kitten heart β1- and β2-adrenoceptors (−)-Adrenaline (−)-Noradrenaline CGP 20,712 A 

Abbreviations

β1AR

β1-adrenoceptor

β2 AR

β2-adrenoceptor

cec

concentration-effect curve

CR

concentration-ratio

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Arunlakshana O, Schild HO (1959) Some quantitative uses of drug antagonists. Br J Pharmacol 14:48–58Google Scholar
  2. Bilski AJ, Halliday SE, Fitzgerald JD, Wale JL (1983) The pharmacology of a β2-selective adrenoceptor antagonist (ICI 118,551). J Cardiovasc Pharmacol 5:430–437Google Scholar
  3. Blinks JR (1965) Convenient apparatus for recording contractions of isolated muscle. J Appl Physiol 20:755–757Google Scholar
  4. Bonelli J (1978) Demonstration of two different types of β1-receptors in man. Selective blockade of the positive inotropic and positive chronotropic effect of isoproterenol. Int J Clin Pharmacol 16:313–319Google Scholar
  5. Brown AM, Birnbaumer L (1988) Direct G protein gating of ion channels. Am J Physiol 23:H401–410Google Scholar
  6. Brick I, Hutchison KJ, McDevitt DG, Roddie IC, Shanks RG (1968) Comparison of the effects of ICI 50172 and propranolol on the cardiovascular responses to adrenaline, isoprenaline and exercise. Br J Pharmacol 34:127–140Google Scholar
  7. Bristow MR, Ginsburg R, Umans V, Fowler M, Minobe W, Rasmussen R, Zera P, Menlove R, Shah P, Jamieson S, Stinson EB (1986) Beta-1 and beta-2 adrenergic receptor subpopulations in nonfailing and failing human ventricular myocardium-coupling of both receptor subtypes to muscle contraction and selective beta-1 receptor down regulation in heart failure. Circ Res 59:297–309Google Scholar
  8. Brodde O-E-Karad K, Zerkowski H-R, Rohm N, Reidemeister JC (1983) Coexistence of β1- and β2-adrenoceptors in human right atrium. Direct identification by (β)-[125I] iodocyanopindolol binding. Circ Res 53:752–758Google Scholar
  9. Buxton BF, Jones CR, Molenaar P, Summers RJ (1987) Characterisation and autoradiographic localization of beta-adrenoceptors in human cardiac tissues. Br J Pharmacol 92:299–310Google Scholar
  10. Carlsson E, Ablad B, Brandstrom A, Carlsson B (1972) Differentiated blockade of the chronotropic effects of various adrenergic stimuli in the cat heart. Life Sci 11:953–958Google Scholar
  11. Dooley DJ, Bittiger H, Reymann NC (1986) CGP 20,712 A: a useful tool for quantitating β1- and β2-adrenoceptors. Eur J Pharmacol 130:137–139Google Scholar
  12. Ehle B, Lemoine H, Kaumann AJ (1985) Improved evaluation of binding of ligands to membranes containing several receptor subtypes. Naunyn-Schmiedeberg's Arch Pharmacol 331:52–59Google Scholar
  13. Emorine LJ, Marullo S, Briend-Sutren MIM, Patey G, Tate K, Delavier-Klutchko C, Strosberg AD (1989) Molecular characterisation of the human β3-adrenergic receptor. Science 245:1118–1121Google Scholar
  14. England PJ (1983) Phosphorylation of cardiac muscle contractile proteins. In: Drake-Holland AJ, Noble MM (eds) Cardiac metabolism. John Wiley, New York, pp 365–389Google Scholar
  15. Freissmuth M, Hausleithner V, Nees S, Bock M, Schütz W (1986) Cardiac ventricular β2-adrenoceptors in guinea pigs and rats are localized on the coronary endothelium. Naunyn-Schmiedeberg's Arch Pharmacol 334:56–62Google Scholar
  16. Gille E, Lemoine H, Ehle B, Kaumann AJ (1985) The affinity of (−)-propranolol for β1- and β2-adrenoceptors of human heart. Differential antagonism of the positive inotropic effects and adenylate cyclase stimulation by (−)-noradrenaline and (−)-adrenaline. Naunyn-Schmiedeberg's Arch Pharmacol 331:60–70Google Scholar
  17. Hall JA, Petch MC, Brown MJ (1989) Intracoronary injections of salbutamol demonstrate the presence of functional β2-adrenoceptors in the human heart. Circ Res 65:546–553Google Scholar
  18. Hall J, Kaumann AJ, Brown MJ (1990) Selective β-adrenoceptor blockade enhances positive inotropic responses to endogenous catecholamines mediated through β2-adrenoceptors in human atrial myocardium. Circ Res 66:1610–1623Google Scholar
  19. Hedberg A, Minneman KP, Molinoff PB (1980) Differential distribution of beta-1 and beta-2 adrenergic receptors in cat and guinea-pig heart. J Pharmacol Exp Ther 212:503–508Google Scholar
  20. Heitz A, Schwartz J, Velly J (1983) β-Adrenoceptors of human myocardium: determination of β1- and β2-subtypes by radioligand binding. Br J Pharmacol 80:711–717Google Scholar
  21. Kaumann AJ (1972) Potentiation of the effect of isoprenaline and noradrenaline by hydrocortisone in cat heart mucle. Naunyn-Schmiedeberg's Arch Pharmacol 273:134–153Google Scholar
  22. Kaumann AJ (1978) On spare β-adrenoceptors for inotropic effects of catecholamines in kitten ventricle. Naunyn-Schmiedeberg's Arch Pharmacol 305:97–102Google Scholar
  23. Kaumann AJ (1986) The β1-adrenoceptor antagonist CGP 20,712A unmasks β2-adrenoceptors activated by (−)-adrenaline in rat sinoatrial node. Naunyn-Schmiedeberg's Arch Pharmacol 333:73–76Google Scholar
  24. Kaumann AJ (1989) Is there a third β-adrenoceptor? Trends Pharmacol Sci 10:316–320Google Scholar
  25. Kaumann AJ, Birnbaumer L (1974) Characteristics of the adrenergic receptor coupled to myocardial adenylyl cyclase. Stereospecificity and determination of apparent affinity constants for beta-blockers. J Biol Chem 249:7874–7885Google Scholar
  26. Kaumann AJ, Lemoine H (1985) Direct labelling of β1-adrenoceptors: Comparison of binding affinity of 3H-(−)bisoprolol with its blocking potency in kitten heart. Naunyn-Schmiedeberg's Arch Pharmacol 331:27–39Google Scholar
  27. Kaumann AJ, Lemoine H (1987) β2-Adrenoceptors-mediated positive inotropic effect of adrenaline in human ventricular myocardium. Quantitative discrepancies with binding and adenylate cyclase stimulation. Naunyn-Schmiedeberg's Arch Pharmacol 335:403–411Google Scholar
  28. Kaumann AJ, Lobnig BM (1986) Mode of action of (−)-pindolol on feline and human myocardium. Br J Pharmacol 89:207–218Google Scholar
  29. Kaumann AJ, Marano M (1982) On equilibrium constants for complexes of drug-receptor subtypes. Selective and non-selective interactions of partial agonists with two plausible β-adrenoceptor subtypes mediating positive chronotropic effects of (−)-isoprenaline in kitten atria. Naunyn-Schmiedeberg's Arch Pharmacol 318:192–201Google Scholar
  30. Kaumann AJ, Birnbaumer L, Wittmann R (1978) Heart β1-adrenoceptors. In: Birnbaumer L, O'Malley BW (eds) Hormone receptors, vol 3. Academic Press, New York, pp 133–177Google Scholar
  31. Kaumann AJ, Morris TH, Bojar H (1983) Heart β-receptors: On the functional role of heterogenous binding sites. J Receptor Res 3:61–70Google Scholar
  32. Kaumann AJ, Lemoine H, Schwederski-Menke, Ehle B (1989a) Relations between β-adrenoceptor occupancy and increases of contractile force and adenylate cyclase activity induced by catecholamines in human ventricular myocardium. Naunyn-Schmiedeberg's Arch Pharmacol 339:99–112Google Scholar
  33. Kaumann AJ, Hall JA, Murray KJ, Wells FC, Brown MJ (1989b) A comparison of the effects of adrenaline and noradrenaline on human heart: the role of β1 and β2-adrenoceptors in the stimulation of adenylate cyclase and contractile force. Eur Heart J 10 [Suppl B]:29–37Google Scholar
  34. Lemoine H, Kaumann AJ (1983) A model for the interaction of competitive antagonists with two receptor-subtypes characterized by Schild-plot with apparent slope unity. Agonist-dependent enantiomeric affinity ratios for bupranolol in tracheae but not in right atria of guinea pigs. Naunyn-Schmiedeberg's Arch Pharmacol 322:111–120Google Scholar
  35. Lemoine H, Kaumann AJ (1986) Relative contribution of β1- and β2-adrenoceptors to the effects of (−)-adrenaline in kitten heart. Pflügers Arch 406:R35Google Scholar
  36. Lemoine H, Ehle B, Kaumann AJ (1985) Direct labelling of β2-adrenoceptors: Comparison of binding potency of 3H-ICI 118,551 and blocking potency of ICI 118,551. Naunyn-Schmiedeberg's Arch Pharmacol 331:40–51Google Scholar
  37. Lemoine H, Schonell H, Kaumann AJ (1988) Contribution of β1- and β2- adrenoceptors of human atrium and ventricle to the effects of noradrenaline and adrenaline as assessed with (−)-atenolol. Br J Pharmacol 95:55–66Google Scholar
  38. Lemoine H, Teng KJ, Slee SJ, Kaumann AJ (1989 a) On minimum cyclic AMP formation rates associated with positive inotropic effects mediated through β1-adrenoceptors in kitten myocardium. β1-specific and non-adrenergic stimulant effects of denopamine. Naunyn-Schmiedeberg's Arch Pharmacol 339:113–128Google Scholar
  39. Lemoine H, Novotny GEK, Kaumann AJ (1989b) Neuronally released (−)-noradrenaline relaxes smooth muscle of calf trachea mainly through β1-adrenoceptors: Comparison with (−)-adrenaline and relation to adenylate cyclase stimulation. Naunyn-Schmiedeberg's Arch Pharmacol 339:85–98Google Scholar
  40. Lowry OW Rosebrough NJ, Farr AL, Randall RJ (1951) Protein measurements with the Folin phenol reagent. J Biol Chem 193:265–275Google Scholar
  41. McCaffrey PM, Riddel JG, Shanks RG (1988) The selectivity of xamoterol, prenalterol and salbutamol as assessed by their effects in the presence and absence of ICI 118,551. J Cardiovasc Pharmacol 11:543–551Google Scholar
  42. Minneman KP, Hegstrand LR, Molinoff PB (1979) Simultaneous determination of β1- and β2-adrenoceptors in tissues containing both subtypes. Mol Pharmacol 16:34–46Google Scholar
  43. Molenaar P, Summers RJ (1987) Characterisation of β-1, and ¬-2 adrenoceptors in guinea-pig atrium: functional and receptor binding studies. J Pharmacol Exp Ther 241:1041–1047Google Scholar
  44. Morris TH, Sandrock K, Kaumann AJ (1981) 3H-(−)-Bupranolol, a new β-adrenoceptor radioligand: Characterisation of its binding to kitten heart β-adrenoceptors. Naunyn-Schmiedeberg's Arch Pharmacol 317:19–25Google Scholar
  45. Salomon Y, Londos C, Rodbell M (1974) A highly sensitivity adenylate cyclase assay. Anal Biochem 58:541–548Google Scholar
  46. Stephenson RP (1956) A modification of receptor theory. Br J Pharmacol 11:379–393Google Scholar
  47. Stephenson JA, Summers RJ (1987) Autoradiographic analysis of receptors on vascular endothelium. Eur J Pharmacol 134:35–43Google Scholar
  48. Tomlins B, Harding SE, Kirby MS, Poole-Wilson PA, Williams AJ (1986) Contamination of a cardiac sacrolemmal preparation with endothelial plasma membrane. Biochim Biophys Acta 856:137–143Google Scholar
  49. Waud DR (1968) Pharmacological receptors. Pharmacol Rev 20:49–88WGoogle Scholar
  50. ellstein A, Belz GG, Palm D (1988) Beta adrenoceptor subtype binding activity in plasma and beta blockade by propranolol and beta-1 selective bisoprolol in humans. Evaluation with Schild plots. J Pharmacol Exp Ther 246:328–337Google Scholar
  51. Yatani A, Codina J, Huoto Y, Reeves JP, Birnbaumer L, Brown AM (1987) A G protein directly regulates mammalian cardiac calcium channels. Science 238:1288–1292Google Scholar
  52. Yatani A, Imoto Y, Codina J, Hamilton S, Brown AM, Birnbaumer L (1988) The stimulatory G protein of adenylyl cyclase, Gs, also stimulates dihydropyridine-sensitive calcium channels: Evidence for direct regulation independent of phosphorylation by CAMP dependent protein kinase or stimulation by a dihydropyridine agonist. J Biol Chem 263:9887–9895Google Scholar

Copyright information

© Springer-Verlag 1991

Authors and Affiliations

  • H. Lemoine
    • 1
  • A. J. Kaumann
    • 2
  1. 1.Institut für Lasermedizin, Heinrich-Heine-Universität Düsseldorf 1DusseldorfFederal Republic of Germany
  2. 2.SmithKline Beecham PharmaceuticalsHertfordshireUK

Personalised recommendations