Skip to main content

Ca-Agonists: a new class of inotropic drugs

  • Conference paper
Inotropic Stimulation and Myocardial Energetics
  • 49 Accesses

Summary

The basic pharmacology of dihydropyridine Ca-agonists published so far (BAY k8644, CGP 28–392, H 160/51, YC 170, and 202–791) is described. The importance of the potency of the enantiomeres for the effect of a racemic compound is underlined.

The Ca agonist prototype BAY k8644 leads to an increase of the maximal rate of rise of left ventricular pressure (LV(dP/dt)) and an increase of left ventricular stroke work in conscious dogs. When the vascular effects of BAY k8644 are counterbalanced by intravenous injection of sodiumnitroprusside, the left ventricular functions curves show markedly increased stroke work against the same mean arterial blood pressure at the same filling pressure.

BAY k8644 stimulates the heart economically: the net efficiency in isolated working guinea-pig hearts is about 20%, identical to a stimulation by calcium or ouabain. Cardiotonic drugs acting via cAMP-dependent mechanisms like isoprenaline, amrinone, or pimobendane however, stimulate the heart about 1/3 less economically.

The mechanism of action of Ca-agonists is explained from electrophysiological findings: Ca-agonistic dihydropyridines increase the open probability of the Ca-channels by a shift of the open-probability curve to more negative membrane potentials. As a consequence, the steady-state inactivation curve of the Ca-channel is also shifted in the same direction. While the effect on open-probability is the underlying mechanism for Ca-agonism, the latter effect results in Ca-antagonism. Therefore, depending on drug concentration and on membrane resting potential, a single chemical compound can act either as a Ca-agonist or a Ca-antagonist. A kinetic model of dihydropyridine action on the Ca-channel is described.

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 39.99
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 54.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Bechem M, Pott L (1985) Removal of Ca-current inactivation in dialyzed guinea-pig atrial cardioballs by Ca-chelators. Pflügers Arch 404: 10–20

    Article  PubMed  CAS  Google Scholar 

  2. Bechem M, Schramm M (1987) Calcium Agonists. J Mol Cell Cardiol 19 (Suppl II): 63–75

    Article  PubMed  CAS  Google Scholar 

  3. Bechem M, Schramm M (1988) The effects of Ca-agonists and Ca-antagonists on the Ca-current. In: Piper HM, Isenberg G (eds) isolated adult cardiomyocytes. CRC Press (in press)

    Google Scholar 

  4. Bellemann P, Ferry D, Lübbecke F, Glossmann H (1981) 3H-Nitrendipine, a potent calcium channel antagonist binds with high affinity to cardiac membranes. Arzneim Forsch/Drug Res 31: 2064–2067

    Google Scholar 

  5. Beyer T, Gansohr N, Gjörstrup P, Ravens U (1986) The effects of the cardiotonic dihydropyridine derivatives BAY k8644 and H160/51 on post-rest adaptation of guinea-pig papillary muscles. Naunyn-Schmiedeberg’s Arch Pharmacol 334: 488–495

    Article  PubMed  CAS  Google Scholar 

  6. Beyer T, Gjörstrup P, Ravens U (1985) Comparison of the cardiac effects of the dihydropyridine-derivative H160/51 with those of the “Ca-agonist” BAY k8644. Naunyn-Schmiedeberg’s Arch Pharmacol Suppl 330: R34

    Google Scholar 

  7. Campbell AK (1983) Intracellular calcium: its universal role as regulator. Wiley, New York

    Google Scholar 

  8. Curtis BM, Catterall WA (1984) Purification of the calcium antagonist receptor of the voltage-sensitive calcium channel from skeletal muscle transverse tubules. Biochemistry 23: 2113–2118

    Article  PubMed  CAS  Google Scholar 

  9. Erne P, Burgisser E, Bühler FR, Dubach B, Kühnis H, Meier M, Rogg N (1984) Enhancement of calcium influx in human platelets by CGP 28392, a novel dihydropyridine. Biochem Biophys Res Comm 118: 842–847

    Article  PubMed  CAS  Google Scholar 

  10. Franckowiak G, Bechem M, Schramm M, Thomas G (1985) The optical isomers of the 1,4-dihydropyridine BAY k8644 show opposite effects on Ca-channels. Europ J Pharmacol 114: 223226

    Google Scholar 

  11. Gjörstrup P (1985) Effects of H160/51, a new Ca-agonist, and its interaction with felodipine on cardiac and vascular tissue in vitro. Proc Cardiovascular Pharmacotherapy. Intern Symposium Geneva April 22–25, Abstr. 127

    Google Scholar 

  12. Gjörstrup P, Harding H, Isaksson R, Westerlund C (1986) The enantiomers of the dihydropyridine derivative H160/51 show opposite effects of stimulation and inhibition. Eur J Pharmacol 122: 357–361

    Article  PubMed  Google Scholar 

  13. Glossmann H, Ferry DR, Goll A, Striessnig J, Schober M (1985) Calcium channels: basic properties as revealed by radioligand binding studies. J Cardiovasc Pharmacol 7 Suppl 6: S20 — S30

    Article  Google Scholar 

  14. Gross R, Kayser M, Schramm M, Taniel R, Thomas G (1985) Cardiovascular effects of the Calcium-agonistic dihydropyridine BAY k8644 in conscious dogs. Arch Internat Pharmacodyn Ther 277: 203–216

    CAS  Google Scholar 

  15. Haas H, Härtfelder G (1962) c-Isopropyl-c-(N-methyl-homoveratryl)-y-aminopropyl-3,4-dimethoxy-phenylacetonitril, eine Substanz mit coronargefäßerweiternden Eigenschaften. Arzneim Forsch 12: 549–558

    Google Scholar 

  16. Hess P, Lansmann JB, Tsien RW (1984) Different modes of calcium channel gating behaviour favoured by dihydropyridine Ca agonists and antagonists. Nature 311: 538–544

    Article  PubMed  CAS  Google Scholar 

  17. Hof RP, Rüegg UT, Hof A, Vogel A (1985) Stereoselectivity at the calcium channel: opposite action of the enantiomeres of a 1,4-dihydropyridine. J Cardiovasc Pharmacol 7: 689–693

    Article  PubMed  CAS  Google Scholar 

  18. Kokobun S, Reuter H (1984) Diyhdropyridines derivatives prolong the open state of Ca channels in cultured cells. Proc Natl Acad Sci USA 81: 482–527

    Google Scholar 

  19. Marty A, Neher E (1983) Tight-seal whole-cell recording. In: Sakmann B, Neher E (eds) Single channel recording. Plenum, New York, pp 107–122

    Chapter  Google Scholar 

  20. Nakaya H, Hattori Y, Tohse N, Kanno M (1986) Voltage-dependent effects of YC-170, a dihydropyridine calcium channel modulator in cardiovascular tissue. Naunyn-Schmiedeberg’s Arch Pharmacol 333: 421–430

    Article  PubMed  CAS  Google Scholar 

  21. Preuss KC, Brooks HL, Gross GJ, Warltier DC (1985) Positive inotropic actions of the calcium channel stimulator, BAY k8644, in the awake, unsedated dog. Bas Res Cardiol 80: 326–332

    Article  CAS  Google Scholar 

  22. Preuss KC, Chung NL, Brooks HL, Warltier DC (1984) Cardiovascular effects of the nifedipine analog CGP 28392 in the conscious dog. J Cardiovasc Pharmacol 6: 949–953

    Article  PubMed  CAS  Google Scholar 

  23. Rasmussen H, Barret PQ (1984) Calcium messenger system: an integrated view. Physiol Rev 64: 938–984

    PubMed  CAS  Google Scholar 

  24. Sanguinetti MC, Kass RS (1984) Regulation of cardiac calcium channel current and contractile activity by the dihydropyridine BAY k8644 is voltage dependent. J Mol Cell Cardiol 16: 667670

    Google Scholar 

  25. Sarnoff SJ, Mitchell JH (1961) The control of the function of the heart. In: Handbook of physiology, circulation sect 2, vol 1. Am Physiol Soc, Washington

    Google Scholar 

  26. Schramm M, Thomas G, Towart R, Franckowiak G (1983) Novel dihydropyridines with positive inotropication through activation of Ca’ channels. Nature 303: 535–537

    Article  PubMed  CAS  Google Scholar 

  27. Schramm M, Thomas G, Towart R, Franckowiak G (1983) Activation of calcium channels by novel 1,4-dihydropyridines. Arzneim-Forsch 33: 1268–1272

    CAS  Google Scholar 

  28. Schramm M, Towart R (1985) Modulation of calcium channel function by drugs. Life Sci 37: 1843–1860

    Article  PubMed  CAS  Google Scholar 

  29. Schramm M, Towart R (1988) Calcium channels as drug receptors. In: Baker PF (ed) Handbook of experimental pharmacology, vol 83. Springer, Berlin Heidelberg New York, pp 89–114

    Google Scholar 

  30. Siess M, Stieler K, Seifart HJ (1981) Zur Wirkung von ARL-115 BS auf Funktion and Sauerstoffverbrauch isolierter Meerschweinchenherzvorhöfe im Vergleich zu g-Strophantin and Theophyllin. Arzneim Forsch/Drug Res 31: 165–170

    CAS  Google Scholar 

  31. Takenaka T, Maeno H (1982) A new vasoconstrictor 1,4-dihydropyridine derivative, YC-170. Jap J Pharmacol 132: 139 P

    Google Scholar 

  32. Tanabe T, Takeshima H, Mikami A, Flockerzi V, Takahashi H, Kangawa K, Kojima M, Matsuo H, Hirose T, Numa S (1987) Primary structure of the receptor for calcium channel blockers from skeletal muscle. Nature 328: 313–318

    Article  PubMed  CAS  Google Scholar 

  33. Thomas G, Groß R, Schramm M (1984) Calcium channel modulation: ability to inhibit or promote calcium influx resides in the same dihydropyridine molecule. J Cardiovasc Pharmacol 6: 1170–1176

    PubMed  CAS  Google Scholar 

  34. Thomas G, Chung M, Cohen CJ (1985) A dihydropyridine (BAY k8644) that enhances calcium currents in guinea pig and calf myocardial cells. Circ Res 56: 87–96

    Article  PubMed  CAS  Google Scholar 

  35. Thomas G, Groß R, Pfitzer G, Rüegg JC (1985) The positive inotropic dihydropyridine BAY k8644 does not affect calcium sensitivity or calcium release of skinned cardiac fibres. NaunynSchmiedeberg’s Arch Pharmacol 328: 378–381

    Article  CAS  Google Scholar 

  36. Triggle DJ, Janis RA (1987) Calcium channel ligands. Rev Pharmacol Toxicol 27: 347–369

    Article  CAS  Google Scholar 

  37. Vater W, Kroneberg G, Hoffmeister F, Kaller H, Meng K, Oberdorf A, Puls W, Schloßmann K, Stoepel K (1972) Zur Pharmakologie von 4-(2’Nitrophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarbonsäuredimethylester (Nifedipin, BAY a1040). Arzneim Forsch 22: 1–14

    CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Editor information

Hj. Just Ch. Holubarsch H. Scholz

Rights and permissions

Reprints and permissions

Copyright information

© 1989 Springer-Verlag Berlin Heidelberg

About this paper

Cite this paper

Bechem, M., Gross, R., Hebisch, S., Schramm, M. (1989). Ca-Agonists: a new class of inotropic drugs. In: Just, H., Holubarsch, C., Scholz, H. (eds) Inotropic Stimulation and Myocardial Energetics. Steinkopff, Heidelberg. https://doi.org/10.1007/978-3-662-07908-9_10

Download citation

  • DOI: https://doi.org/10.1007/978-3-662-07908-9_10

  • Publisher Name: Steinkopff, Heidelberg

  • Print ISBN: 978-3-662-07910-2

  • Online ISBN: 978-3-662-07908-9

  • eBook Packages: Springer Book Archive

Publish with us

Policies and ethics