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A Novel Background Potassium Channel in Rat Atrial Cells
Author(s) -
Shui Z.,
Boyett M. R.
Publication year - 2000
Publication title -
experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0958-0670
DOI - 10.1111/j.1469-445x.2000.02034.x
Subject(s) - potassium channel , potassium , chemistry , medicine , biophysics , cardiology , biology , organic chemistry
A K+ channel activated by intracellular ATP has been observed in inside‐out patches from rat atrial cells. The channel has a slope conductance of 130 ± 5 pS in symmetrical 140 mM K+ solution, and is almost independent of voltage over the range from ‐80 to +80 mV. There is no detectable inactivation during application of ATP over a few minutes. In the presence of 3 mM intracellular ATP, channel openings occur as bursts with a mean open time of 1.7 ms, a mean closed time of 0.4 ms, a mean burst duration of 18 ms and a mean burst interval of 41 ms. Kinetic analysis suggests that ATP mainly affects the burst duration and the burst interval of the channel. Based on the properties above, the channel differs from other known K+ channels in cardiac cells and may contribute to background K+ current.