Abstract
Acetylcholine (ACh) released on vagal stimulation1 reduces the heart rate by increasing K+ conductance of pacemaker cells in the sinoatrial (S-A) node2,3. Fluctuation analysis of ACh-activated currents in pacemaker tissue showed this to be due to opening of a separate class of K+ channels gated by muscarinic ACh receptors (m-AChRs)4. On the other hand, it has been suggested that m-AChRs may simply regulate the current flow through inward rectifying resting K+ channels (gK1)5,6. We report here the measurement of ACh-activated single channel K+ currents and of resting K+ channel currents in isolated cells of the atrioventricular (A-V) and S-A node of rabbit heart. The results show that the ACh-dependent K+ conductance increase in nodal cells is mediated by K+ channels which are different in their gating and conductance properties from the inward rectifying resting K+ channels in atrial and ventricular cells. The resting K+ channels in nodal cells are, however, similar to those activated by ACh.
This is a preview of subscription content, access via your institution
Relevant articles
Open Access articles citing this article.
-
Gender Differences in Cardiac Chronotropic Control: Implications for Heart Rate Variability Research
Applied Psychophysiology and Biofeedback Open Access 24 November 2021
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Rent or buy this article
Get just this article for as long as you need it
$39.95
Prices may be subject to local taxes which are calculated during checkout
References
Loewi, O. & Navratil, E. Pflügers Arch. ges. Physiol. 214, 678–688 (1926).
Hutter, O. F. in Nervous Inhibition (ed. Florey, E.) 114–123 (Pergamon, Oxford, 1961).
Trautwein, W. & Dudel, J. Pflügers Arch. ges. Physiol. 266, 324–334 (1958).
Noma, A., Peper, K. & Trautwein, W. Pflügers Arch. ges. Physiol. 381, 255–262 (1979).
Garnier, D., Nargeot, J., Ojeda, C. & Rougier, O. J. Physiol., Lond. 274, 381–396 (1978).
Ojeda, C., Rougier, O. & Tourneur, Y. Pflügers Arch. ges. Physiol. 391, 57–59 (1981).
Taniguchi, J., Kokubun, S., Noma, A. & Irisawa, H. Jap. J. Physiol. 31, 547–558 (1981).
Hamill, O. P., Marty, A., Neher, E., Sakmann, B. & Sigworth, F. J. Pflügers Arch. ges. Physiol. 391, 85–100 (1981).
Noma, A. & Trautwein, W. Pflügers Arch. ges. Physiol. 377, 193–200 (1978).
Conti, F. & Neher, E. Nature 285, 140–143 (1980).
Osterrieder, W., Noma, A. & Trautwein, W. Pflügers Arch. ges. Physiol. 386, 101–109 (1980).
Trube, G., Sakmann, B. & Trautwein, W. Pflügers Arch. ges. Physiol. 291, R28 (1981).
Colquhoun, D. & Sakmann, B. Nature 294, 464–466 (1981).
del Castillo, J. & Katz, B. Proc. R. Soc. B146, 369–381 (1957).
Colquhoun, D. & Hawkes, A. G. Proc. R. Soc. B199, 231–262 (1977).
Colquhoun, D. & Hawkes, A. G. Proc. R. Soc. B211, 205–235 (1981).
Halvorsen, S. W. & Nathanson, N. M. J. biol. Chem. 256, 7941–7948 (1981).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Sakmann, B., Noma, A. & Trautwein, W. Acetylcholine activation of single muscarinic K+ channels in isolated pacemaker cells of the mammalian heart. Nature 303, 250–253 (1983). https://doi.org/10.1038/303250a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/303250a0
This article is cited by
-
Gender Differences in Cardiac Chronotropic Control: Implications for Heart Rate Variability Research
Applied Psychophysiology and Biofeedback (2022)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.
