depolarized

Bisaramil hydrochloride (Bisaramil) is a novel diazabicyclononane antiarrhythmic compound that inhibits the generation of free radicals.Bisaramil hydrochloride blocks sodium currents and inhibits the slow Ca(2+) action potential induced by isoproterenol in K(+)-depolarized muscle.

SR33805 is a potent antagonist of Ca2+ channel(EC50s of 4.1 nM and 33 nM in depolarized and polarized conditions, respectively)

F 15845 is a blocker of the persistent sodium current prevents consequences of hypoxia in rat femoral artery. F15845 has been shown to selectively inhibit the persistent sodium current of Nav1.5[1] exerting cardioprotective effects following ischemia. In vitro testing showed minimal effects of F15845 on other important ion channels of the heart, including major Ca2+ and K+ channels.[1] This characteristic is thought to account for the limited effect of F15845 to change other heart parameters such as basal cardiac function, hemodynamic functions and ventricular fibrillation. F15845 was also shown to exert improved effects when the membrane potential was depolarized,[1] by acting on the extracellular side of the channel.

Nicorandil-d4 is intended for use as an internal standard for the quantification of nicorandil by GC- or LC-MS. Nicorandil is an activator of sulfonylurea receptor 2B (SUR2B) linked to ATP-sensitive potassium channel Kir6.2 (EC50 = ~10 µM) and a nitric oxide (NO) donor. It is selective for SUR2B/Kir6.2 over the SUR2A/Kir6.2 channel (EC50 = >500 µM). Nicorandil activates soluble guanylate cyclase in a cell-free assay and relaxes partially depolarized isolated bovine coronary artery strips (EC50 = 4.4 µM). It decreases mean blood pressure, coronary resistance, and heart rate, as well as increases coronary sinus outflow, in dogs when administered intravenously at a dose of 1 mg/kg. Nicorandil increases survival and decreases infarct size in a rabbit model of myocardial ischemia-reperfusion injury induced by left coronary artery occlusion. Formulations containing nicorandil have been used in the treatment of angina pectoris.

Guangxitoxin 1E acts as a gating modifier since it shifts the voltage-dependence of Kv2.1 K+ currents towards depolarized potentials.

Nicorandil (SG-75)(Ikorel) acts by relaxing the smooth muscle of the blood vessels, especially those of the venous system. It undertakes this through two methods. Firstly, by activating potassium channels, and secondly by donating nitric oxide to activate the enzyme guanylate cyclase. Guanylate cyclase causes activation of cGMP leading to both arterial and venous vasodilatation by de-phosphorylation of the myosin light chain.