NS1652 is a reversible anion conductance inhibitor, blocks chloride channel, with an IC50 of 1.6 μM in human and mouse red blood cells.
NS1652 potently inhibits the chloride conductance (IC50, 1.6 μM) in human and mouse red blood cells, but only weakly inhibits VRAC (IC50, 125 μM) in HEK293 cells. NS1652 markedly blocks the NO production with an IC50 of 3.1 μM in BV2 cells. NS1652 also down-regulates iNOS expression at 3 μM, and completely abolishes at 10 μM in BV2 cells[1]. NS1652 (0, 1.0, 3.3, 10, and 20 μM) causes increasing hyperpolarization due to inhibition of the chloride conductance in normal erythrocytes. NS1652 lowers the net KCl loss from deoxygenated sickle cells from about 12 mM cells/h to about 4 mM cells/h. NS1652 (20 μM) completely and reversiblely inhibits the red cell Cl-conductance[2].
NS1652 (50 mg/kg, i.v.) blocks murine erythrocyte Cl- conductance by >90% in mice[2].
[1]. Kjaer K, et al. Chloride channel blockers inhibit iNOS expression and NO production in IFNgamma-stimulated microglial BV2 cells. Brain Res. 2009 Jul 24;1281:15-24. [2]. Bennekou P, et al. Volume control in sickle cells is facilitated by the novel anion conductance inhibitor NS1652. Blood. 2000 Mar 1;95(5):1842-8.