Changes of the subsarcolemmal Na+ concentration in internally perfused cardiac cells.
Transients of Na+/K+ pump and of Na+/Ca2+ exchange current occur during whole-cell recording from cardiac cells upon quick changes of active Na+ efflux. The transients reflect a temporary loss of control of the subsarcolemmal Na+ concentration. Even in the steady state the control is not complete is certain cells. Quantitative studies on ion transport by whole-cell recording are meaningful only if an adequate control of the submembranal ionic composition is demonstrated.
Bielen
F V
FV
Interdisciplinary Research Centre, Catholic University of Leuven, Kortrijk, Belgium.
Glitsch
H G
HG
Verdonck
F
F
D000818:Animals; D001693:Biological Transport, Active; D002118:Calcium / Q000378:metabolism; D004553:Electric Conductivity; D006352:Heart Ventricles / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism; D011689:Purkinje Cells / Q000378:metabolism; D011817:Rabbits; D012508:Sarcolemma / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism*
D012964:Sodium; D011188:Potassium; D002118:Calcium