[Inward rectifier potassium current in cultured embryonic chick ventricular myocytes and effect of culture time].
The single channel features of inward rectifier potassium current (IK1) in primary cultured embryonic chick ventricular myocytes and the effect of culture time on it were studied by using cell-attached patch clamp technique. The results showed that inward current fluctuation could be recorded at membrane potential negative to the potassium equilibrium potential (EK) and [K+] o = [K+]i = 140 mmol/L. The single channel current-voltage (I-V) relation was linear. The slope conductance was 35 pS (1-3 day culture). But at membrane potential positive to the EK, strong inward rectification was evident. The analysis of open and close time distribution indicated that a close-close-open three state model was appropriate to describe the gating processes of IK1 channel. No significant effect of culture time was observed. The channel density and slope conductance of IK1 were 0.64, 0.76, 0.77 channels/microns and 35, 28, 37 pS corresponding to 1-3, 4-6, and 7-11 day culture period, respectively. This result could partially explain why action potential of cardiomyocytes did not change with culture time.
Cai
Z
Z
Department of Physiology, Luzhou Medical College.
Lan
T
T
Zhu
J
J
Zeng
X
X
D000818:Animals; D001693:Biological Transport, Active; D002478:Cells, Cultured; D002642:Chick Embryo; D008564:Membrane Potentials; D009206:Myocardium / Q000166:cytology*; D015221:Potassium Channels / Q000502:physiology*; D013997:Time Factors
D015221:Potassium Channels