KB-R7943 mesylate is a widely used inhibitor of the reverse Na+/Ca2+ exchanger (NCXrev) with IC50 of 5.7±2.1 μM.

KB-R7943 inhibited NCX(rev) with IC(50) = 5.7 ± 2.1 μM, blocked NMDAR-mediated ion currents, and inhibited NMDA-induced increase in cytosolic Ca(2+) with IC(50) = 13.4 ± 3.6 μM but accelerated calcium deregulation and mitochondrial depolarization in glutamate-treated neurons.?KB-R7943 depolarized mitochondria in a Ca(2+) -independent manner.?Stimulation of NMDA receptors caused NAD(P)H oxidation that was coupled or uncoupled from ATP synthesis depending on the presence of Ca(2+) in the bath solution.?KB-R7943, or rotenone, increased NAD(P)H autofluorescence under resting conditions and suppressed NAD(P)H oxidation following glutamate application.?KB-R7943 inhibited 2,4-dinitrophenol-stimulated respiration of cultured neurons with IC(50) = 11.4 ± 2.4 μM.?With isolated brain mitochondria, KB-R7943 inhibited respiration, depolarized organelles and suppressed Ca(2+) uptake when mitochondria oxidized complex I substrates but was ineffective when mitochondria were supplied with succinate, a complex II substrate[1].

Fluorescence microscopy, electrophysiological patch-clamp techniques and cellular respirometry with Seahorse XF24 analyzer were used with cultured hippocampal neurons;?membrane potential imaging, respirometry and Ca(2+) flux measurements were made in isolated rat brain mitochondria[1].