GUANINE-NUCLEOTIDES PROTECT AGAINST KAINATE TOXICITY IN AN EX-VIVO CHICK RETINAL PREPARATION

Ex vivo preparations of chick neural retina have been successfully use d in the assessment of excitotoxicity and in the evaluation of the pro tective effects of glutamate antagonists. Using a variation of this ap proach, and measuring the acute and delayed toxic effects of kainate ( KA) in terms of lactate dehydrogenase release, we have shown that guan ine nucleotides behave as effective neuroprotecting agents, The anti-e xcitotoxic potency of guanine nucleotides (in the case of GMP and GDP beta S it is about 100 times lower than that of DNQX, a powerful kaina te antagonist) correlates well with their ability to displace KA from retinal KA receptors, (C) 1998 Federation of European Biochemical Soci eties.