154106-92-0

RPR104632 antagonizes the binding of [ ³ H]5,7-dichlorokynurenic acid to the rat cerebral cortex, with a K _i of 4.9 nM. RPR104632 inhibits [ ³ H]N-[1-(2-thienyl)cyclohexyl]-3,4-piperidine ([ ³ H]TCP) binding in the presence of N-methyl-D-aspartate (NMDA) (IC ₅₀ = 55 nM). RPR104632 inhibits the NMDA-evoked increase in guanosine 3',5'-cyclic monophosphate (cGMP) levels of neonatal rat cerebellar slices (IC ₅₀ = 890 nM) in a non-competitive manner and markedly reduces NMDA-induced neurotoxicity in rat hippocampal slices and in cortical primary cell cultures. MK-801 (1 μM) completely protects the CA1 and CA3 pyramidal neurones against NMDA-induced toxicity, but these effects are not blocked by glycine. RPR104632 produces a significant and consistent neuroprotective effect towards all the NMDA-induced toxicity and has no effect when it is added alone at concentrations up to 10 μM. RPR104632 has neuroprotective potencies, with EC ₅₀ of 4 μM.