Possible scenarios for localization and effect of the muscle chloride conductance. (A) A T-tubular localization of G_Cl could directly minimize K⁺ accumulation in the T-tubules. (B) In the simple remote control theory, G_Cl controls the T-tubular membrane potential and the tubular [K⁺] from its sarcolemmal localization. (C) A possible mechanism by which T-tubular outwardly rectifying K⁺ channels mediate fast AP repolarization and inwardly rectifying K channels mediate K⁺ reuptake. The tubular membrane potential is kept negative at rest after cessation of the AP. The inset shows schematically the waveform of an AP.