title: A voltage-dependent gate in series with the inwardly rectifying potassium channel in frog striated muscle.
abstract: 1. The degree of tubular potassium depletion and the decrease of potassium conductance due to hyperpolarizing pulses in striated muscular fibres have been examined with the three micro-electrode voltage-clamp technique. 2. The conductance of the fibre membrane has been measured in different extracellular K+ concentrations from 1 to 10 mM. 3. Comparison of the two sets of measurements shows that changes in tubular K+ concentration are not sufficient to account for the conductance decrease associated with hyperpolarization. 4. The presence of a voltage-dependent gate in series with the inwardly rectifying channel for K+ ions, suggested by Almers (1972a, b), is thus confirmed.
mesh_terms: D000818:Animals; D001001:Anura; D004553:Electric Conductivity; D066298:In Vitro Techniques; D007473:Ion Channels / Q000502:physiology*; D007700:Kinetics; D008564:Membrane Potentials; D008954:Models, Biological; D009132:Muscles / Q000378:metabolism / Q000502:physiology*; D011188:Potassium / Q000378:metabolism* / Q000502:physiology; D011893:Rana esculenta
chemical_list: D007473:Ion Channels; D011188:Potassium