Single K+ channel currents of anomalous rectification in cultured rat myotubes.
- 1 August 1981
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 78 (8), 4960-4964
- https://doi.org/10.1073/pnas.78.8.4960
Abstract
The currents through single K+ channels of the anomalous (or inward) rectifier were recorded in tissue cultured rat myotubes by using the "gigohm seal" patch clamp technique developed by Sigworth and Neher. These unitary currents were detected as current fluctuations due to the blocking and unblocking of channels by Ba2+. The single-channel conductance was obtained from the slope of the linear relationship between unitary current amplitude and membrane potential. When the external solution contained 155 mM K+, the single-channel conductance was 10.4 +/- 2.6 pS (+/- SD; n = 6). This value was independent of the the concentration of blocking ions but increased with increasing external K+ concentration. The behavior of the unitary current agreed with that expected from the blocking kinetics of Ba2+ on the macroscopic K+ current of the anomalous rectifier. The density of the channel is likely to be small and may even be less than 1/micrometers 2.This publication has 18 references indexed in Scilit:
- Unitary current through sodium channel and anomalous rectifier channel estimated from transient current noise in the tunicate egg.The Journal of Physiology, 1981
- Identification and kinetic properties of the current through a single Na+ channel.Proceedings of the National Academy of Sciences, 1981
- Single channel currents from excised patches of muscle membrane.Proceedings of the National Academy of Sciences, 1980
- Single Na+ channel currents observed in cultured rat muscle cellsNature, 1980
- Potassium depletion and sodium block of potassium currents under hyperpolarization in frog sartorius muscle.The Journal of Physiology, 1979
- Blocking effects of barium and hydrogen ions on the potassium current during anomalous rectification in the starfish egg.The Journal of Physiology, 1978
- Single-channel currents recorded from membrane of denervated frog muscle fibresNature, 1976
- Developmental changes of membrane electrical properties in a rat skeletal muscle cell line.The Journal of Physiology, 1975
- The anomalous rectification and cation selectivity of the membrane of a starfish egg cellThe Journal of Membrane Biology, 1974
- Potassium conductance changes in skeletal muscle and the potassium concentration in the transverse tubulesThe Journal of Physiology, 1972