Effect of external K on the block of the inward rectifier during hyperpolarization in guinea-pig ventricular myocytes by external Na.
The effect of changes of the external K concentration on the block of the inward-rectifying K current during hyperpolarization in guinea-pig ventricular myocytes by external Na was investigated. The voltage-dependent block of iK1 by external Na ions is decreased when the external K concentration is lowered between 5.4 and 0.54 mM, but is not influenced when Ko is increased from 5.4 to 27 mM. The effect of lowering Ko can be described as a decrease of the rate of entry of blocking Na ions at lower external K.
Laboratory of Physiology, University Leuven, Belgium.
G
G
Biermans
J
J
Vereecke
E
E
Carmeliet
D000818:Animals; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects*; D066298:In Vitro Techniques; D008297:Male; D009206:Myocardium / Q000166:cytology* / Q000378:metabolism; D011188:Potassium / Q000378:metabolism / Q000494:pharmacology*; D012964:Sodium / Q000494:pharmacology*
D012964:Sodium; D011188:Potassium