Potassium channels in airway smooth muscle: a tale of two channels.

Potassium channels are an important determinant of smooth muscle excitability and force generation. Two potassium channels have been fully described in airway smooth muscle: large conductance, calcium-activated potassium channels and voltage-dependent delayed rectifier channels. This article will review the biophysics and pharmacology of these channels and discuss what is currently known with respect to their regulation and physiological significance.