Selective Na+/Ca2+-exchange (NCX) inhibitor; displays some selectivity for NCX1. IC50 values are 2.9, 16 and 8.6 μM for inhibition of intracellular Na+-dependent 45Ca2+ uptake by cells expressing NCX1, NCX2 and NCX3 respectively. Has some affinity for mACh receptors (IC50 = 18 μM) but minimal activity against NCKX2 and various receptors and ion channels (IC50 > 30 μM). Preferentially blocks Ca2+ influx mode and is more selective for NCX isoforms than KB-R7943 (Cat. No. 1244). Anti-ischemic; potently protects against hypoxia-induced renal tubular cell damage (IC50 = 0.63 μM).