Description_x000D_ Packaging_x000D_ 5, 25 mg in glass bottle_x000D_ Biochem/physiol Actions_x000D_ Mephetyl tetrazole is a potent and selective Kv1.5 potassium channel blocker. IC50 = 330 nM; shows selective atrial prolongation (40%) of effective refractory period (ERP), but no effect on ventricular ERP Kv1.5 channel is a molecular target for the treatment of atrial fibrillation._x000D_ Features and Benefits_x000D_ This compound is also offered as part of Sigma′s Library of Pharmacologically Active Compounds (LOPAC®1280), a biologically annotated collection of high-quality, ready-to-screen compounds. Click here to learn more._x000D_ This compound is featured on the Potassium Channels page of the Handbook of Receptor Classification and Signal Transduction. To browse other handbook pages, click here._x000D_ Legal Information_x000D_ LOPAC is a registered trademark of Sigma-Aldrich Co. LLC