Abstract
An inward current activated by hyperpolarization, IK,H, was studied under voltage clamp in locust skeletal muscle. The dependence of its reversal potential on [K+]o and its insensitivity to changes in [Na+]o indicate that the underlying conductance is a K+ conductance. The instantaneous currentvoltage (I–V)-relationship exhibits outward rectification. Activation and deactivation take seconds and have complex time courses. At 10 mM [K+]o activation seems to start at a voltage ≥ mV more positive than the resting potential (∼ −68 mV). Ba++ blocks IK,H strongly; so do Rb+ and Cs+, the latter in a voltage dependent manner. The slow inward current bears similarities to anomalous rectifiers as well as to mixed, hyperpolarization-activated K+/Na+ currents in other tissues.
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Zittlau, K.E., Walther, C. Hyperpolarization slowly activates a potassium current in locust skeletal muscle. Pflügers Archiv 418, 190–192 (1991). https://doi.org/10.1007/BF00370470
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DOI: https://doi.org/10.1007/BF00370470