Two different types of potassium channels in human skeletal muscle activated by potassium channel openers.

The inside-out patch clamp technique was used to record the effects of K+ channel openers (EMD 52692, RP 49356 and Cromakalim) on single channel currents in membrane blebs of human skeletal muscle. Two types of K+ channels were activated by these drugs: an ATP-sensitive K+ channel which was inhibited by 3 mM ATP and 5 microM Glibenclamide and an ATP insensitive K+ channel. The open probability of both types was strongly increased by K+ channel openers. Glibenclamide antagonized the action of the K+ channel openers.