Summary
The properties of the current if in the cardiac SA node cells are investigated in the light of its resemblance to the current of cardiac Purkinje fibres in their quality of “pacemaker” currents and in their role in mediating the adrenaline-induced acceleration of pacemaker activity. We find that:
- Na removal reduces if, as observed for iK2; furthermore if, like ik2, blocked by cesium
- Despite these similarities, membrane conductance measurements in normal and high K show that if cannot be a pure K-current like ik2. On the contrary, if behaves as an inward current activated on hyper-polarizations below −50/−60 mV from holding potentials near −40 mV.
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© 1980 Plenum Press, New York
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DiFrancesco, D., Ojeda, C. (1980). Properties of the Current (if) which Underlies Adrenaline Action in the SA Node. Comparison with ik2 in the Purkinje Fibre. In: Borsellino, A., Omodeo, P., Strom, R., Vecli, A., Wanke, E. (eds) Developments in Biophysical Research. Springer, Boston, MA. https://doi.org/10.1007/978-1-4684-1077-8_8
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DOI: https://doi.org/10.1007/978-1-4684-1077-8_8
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