Neuroprotective effects of RPR 104632, a novel antagonist at the glycine site of the NMDA receptor, in vitro

Autor: Jean Marie Miquet, Marie-Claude Burgevin, M. Daniel, C. Malgouris, Mireille Meunier, Francoise Bordier, Colette Peny, Gabrielle Durand, Adam Doble, Jean-Charles Blanchard, Alain Boireau, Thierry Chevet, Serge Mignani, Patrick Jimonet
Rok vydání: 1996
Předmět:
Zdroj: European Journal of Pharmacology. 300:237-246
ISSN: 0014-2999
DOI: 10.1016/0014-2999(95)00780-6
Popis: The NMDA antagonist and neuroprotective effects of RPR 104632 (2H-1,2,4-benzothiadiazine-1-dioxide-3-carboxylic acid), a new benzothiadiazine derivative, with affinity for the glycine site of the NMDA receptor-channel complex are described. RPR 104632 antagonized the binding of [3H]5,7-dichlorokynurenic acid to the rat cerebral cortex, with a Ki of 4.9 nM. This effect was stereospecific, since the (-)-isomer was 500-fold more potent than the (+)-isomer. The potent affinity of RPR 104632 for the glycine site was confirmed by the observation that RPR 104632 inhibited [3H]N-[1-(2-thienyl)cyclohexyl]-3,4-piperidine ([3H]TCP) binding in the presence of N-methyl-D-aspartate (NMDA) (IC50 = 55 nM), whereas it had no effect on the competitive NMDA site or on the dissociative anaesthetic site. RPR 104632 inhibited the NMDA-evoked increase in guanosine 3',5'-cyclic monophosphate (cGMP) levels of neonatal rat cerebellar slices (IC50 = 890 nM) in a non-competitive manner and markedly reduced NMDA-induced neurotoxicity in rat hippocampal slices and in cortical primary cell cultures. These results suggest that RPR 104632 is a high-affinity specific antagonist of the glycine site coupled to the NMDA receptor channel with potent neuroprotective properties in vitro.
Databáze: OpenAIRE