Nicorandil (CAS 65141-46-0) is a small molecule that acts as a potassium channel opener and an activator of guanylate cyclase By facilitating potassium efflux nicorandil induces membrane hyperpolarization in vascular smooth muscle cells leading to vasodilation Additionally it enhances intracellular cyclic GMP (cGMP) levels through direct stimulation of guanylate cyclase subsequently activating protein kinase G (PKG) The activation of PKG results in downstream phosphorylation events that inhibit contractile processes in smooth muscle Nicorandil is widely used as a tool compound in cardiovascular research particularly in studies investigating angina vasorelaxation and cellular mechanisms of vascular tone regulation