Pflügers Archiv

, Volume 383, Issue 1, pp 75–77 | Cite as

A kinetic model for the muscarinic action of acetylcholine

  • L. Pott
  • H. Pusch
Excitable Tissues and Central Nervous Physiology Letters and Notes


The timecourse of the membrane hyperpolarization evoked by stimulation of postganglionic parasympathetic nerve endings in isolated atria from the guineapig heart is mainly governed by two exponentials, one describing most of the rising phase (rate constant kα=2.88±1.135 s−1) and one which completely describes the decline of the response (kβ=0.58±0.31 s−1). An exact description of the muscarinic receptor mediated potential change, which also allows for its apparent latency and its s-shaped beginning, is found if two additional faster exponentials are introduced. In agreement with earlier results a model of four consecutive reactions is presented. It is concluded that during muscarinic cholinergic transmission reactions subsequent to binding of the ACh-molecules to the receptor are rate-limiting.

Key words

Acetylcholine Muscarinic receptor Consecutive reaction model Atrial membrane potential 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Bolton, T.B.: On the latency and form of smooth muscle to the iontophoretic application of acetylcholine or carbachol. Proc. R. Soc. Lond. B.,194, 99–119 (1976)Google Scholar
  2. 2.
    Hartzell, H.C., Kuffler, S.W., Stickgold, R., and Yoshikami, D.: Synaptic excitation and inhibition resulting from direct action of acetylcholine on two types of chemorezeptors on individual amphibian parasympathetic neurones. J. Physiol.271, 817–846 (1977).Google Scholar
  3. 3.
    Hill-Smith, I., and Purves, R.D.: Synaptic delay in the heart: An ionophoretic study. J. Physiol.279, 31–54 (1978)Google Scholar
  4. 4.
    Purves, R.D.: Function of muscarinic and nicotinic acetylcholine receptors. Nature261, 149–151 (1976)Google Scholar
  5. 5.
    Pott, L.: On the time course of the acetylcholine-induced hyperpolarization in quiescent guinea-pig atria. Pflügers Arch.380, 71–77 (1979)Google Scholar
  6. 6.
    George, W.J., Polson, J.B., O'Toole, A.G., and Goldberg, N.D.: Elevation of guanosine 3′, 5′-cyclic phosphate in rat heart after perfusion with acetylcholine. Proc. Natl. Acad. Sci. US.,66, 398–403 (1970)Google Scholar
  7. 7.
    Greengard, O.: Possible role for cyclic nucleotides and phosphorylated membrane proteins in postsynaptic actions of neurotransmitters. Nature260, 101–108 (1976)Google Scholar
  8. 8.
    Nawrath, H.: Does cyclic GMP mediate the negative inotropic effect in the heart? Nature267, 72–74 (1977)Google Scholar
  9. 9.
    Benson, S.W.: The foundations of chemical kinetics. McGraw-Hill, New York (1960)Google Scholar
  10. 10.
    Niedergerke, R., and Page, S.: Analysis of catecholamine effects in single atrial trabeculae of the frog heart. Proc. R. Soc. Lond. B.,197, 333–362 (1977)Google Scholar
  11. 11.
    Blackman, J.G., Ginsborg, B.L., and House, C.R.: On the time course of the electrical response of salivary gland cells ofNauphoeta Cinerea to ionophoretically applied dopamine. J. Physiol.287, 81–92 (1979)Google Scholar

Copyright information

© Springer-Verlag 1979

Authors and Affiliations

  • L. Pott
    • 1
  • H. Pusch
    • 1
  1. 1.Institut für ZellphysiologieRuhr-Universität BochumBochumFederal Republic of Germany

Personalised recommendations