THE EFFECT OF AL0671, A NOVEL POTASSIUM CHANNEL OPENER, ON POTASSIUM CURRENT IN RAT AORTIC SMOOTH-MUSCLE CELLS

1. We evaluated the mechanism of activation by AL0671, a novel potassi um channel opener, of potassium current in rat aortic smooth muscle ce lls. 2. Under conditions of whole cell recording, AL0671 (1-1000 mu M) markedly increased potassium current with a Hill coefficient of 2 and dissociation constant of 1.5 x 10(-4) M. This activation was complete ly inhibited by intracellular ATP. 3. Under inside-out patch condition s, the ATP-sensitive K+ channels (K-ATP) treated with AL0671 (100 mu M ) showed prolongation of the slower open time component and shortening of the slower closed time component without modification of channel c onductance.