Small and Intermediate Calcium-Activated Potassium Channel Openers Improve Rat Endothelial and Erectile Function

Modulation of endothelial calcium-activated potassium (K ) channels has been proposed as an approach to restore endothelial function. The present study investigated whether novel openers of K channels with small (K 2.x) and intermediate (K 3.1) conductance, NS309 and NS4591, improve endothelium-dependent relaxation and erectile function. Rat (CC) strips were mounted for isometric tension recording and processed for immunoblotting. Mean arterial pressure (MAP), intracavernosal pressure (ICP), and electrocardiographic (ECG) measurements were conducted in anesthetized rats. Immunoblotting revealed the presence of K 2.3 and large K conductance (K 1.1) channels in the . NS309 and NS4591 increased current in CC endothelial cells in whole cell patch clamp experiments. Relaxation induced by NS309 (