Nicorandil

Nicorandil (SG-75) is a potent potassium channel activator and targets vascular nucleoside diphosphate-dependent K⁺ channels and cardiac ATP-sensitive K⁺ channels (K_ATP). Nicorandil is a nicotinamide ester with vasodilatory and cardioprotective effects and has the potential for angina and forischemic heart diseases^[1][2][3]. IC50 & Target: Potassium Channel^[1]. In Vitro: Nicorandil (SG-75) activates ATP-sensitive K⁺ channels composed of Kir6.2 and either sulfonylurea receptor (SUR) 2A or 2B^[1].
Nicorandil is a vasodilatory drug used to treat angina. Nicorandil (SG-75) stimulates guanylate cyclase to increase formation of cyclic GMP (cGMP). cGMP activates protein kinase G (PKG) which phosphorylates and inhibits GTPase RhoA and decreases Rho-kinase activity. Reduced Rho-kinase activity permits an increase in myosin phosphatase activity, decreasing the calcium sensitivity of the smooth muscle. PKG also activates the sarcolemma calcium pump to remove activating calcium. PKG acts on K+ channels to promote K+ efflux and the ensuing hyperpolarization inhibits voltage-gated calcium channels. Overall, this leads to relaxation of the smooth muscle and coronary vasodilation^[2][3].