Protective effect of KB-R7943, a novel Na+/Ca2+ exchange inhibitor, on ischemic acute renal failure in rats

The effects of KB-R7943 (2-[2-[4-(4-nitrobenzyloxy)phenyl]ethyl] methanesul fonate), a novel Na+/Ca2+ exchange inhibitor, on ischemic acute renal failu re (ARF) in rats were examined. ARF was induced by clamping the left renal pedicle for 45 min followed by reperfusion, 2 weeks after contralateral nep hrectomy. Renal function was markedly diminished in ARF rats. Pretreatment with KB-R7943 (10 mg/kg, i.v.) markedly attenuated the ARF-induced renal dy sfunction. Histopathological examination of the kidney of ARF rats revealed severe renal damage, which was suppressed by KB-R7943. Activation of the r everse mode of Na+/Ca2+ exchange seems to play an important role in the pat hogenesis of ARF. A selective Na+/Ca2+ exchange inhibitor may be useful in cases of ARF.