Inactivation of the ERG current in NG108-15 cells.
Differentiated NG108-15 neuroblastoma x glioma hybrid cells were whole-cell voltage clamped. The rate of inactivation of ERG (ether-à-go-go related gene) potassium channels was measured with a three-pulse protocol. Contamination with delayed rectifier current at positive potentials was avoided by using the selective ERG channel blocker E-4031. The curve relating time constant of inactivation tau to membrane potential V could be fitted by a Gauss curve. In a bath with 40 mM K(+), the curve peaked at V = -36 mV. Lowering [K(+)](o) decreased tau. At V = -20 mV, the average tau was 25.4 ms in 40 mM K(+), 20.6 ms in 6.5 mM K(+), and 15.0 ms in 0 mM K(+). This resembles the relation between tau and [K(+)](o) in ERG channels expressed in Xenopus oocytes.
Meves
H
H
I. Physiologisches, Institut der Universität des Saarlandes, Homburg-Saar, D-66421, Germany.
D000818:Animals; D004553:Electric Conductivity; D005910:Glioma; D006822:Hybrid Cells; D015640:Ion Channel Gating; D051379:Mice; D009447:Neuroblastoma; D016011:Normal Distribution; D018408:Patch-Clamp Techniques; D010880:Piperidines / Q000494:pharmacology; D026902:Potassium Channel Blockers; D015221:Potassium Channels / Q000502:physiology*; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D014407:Tumor Cells, Cultured
D010880:Piperidines; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D011725:Pyridines; C063968:E 4031