Stereoselective neuroprotection by novel 2,3-benzodiazepine non-competitive AMPA antagonists against non-NMDA receptor-mediated excitotoxicity in primary rat hippocampal cultures
| Autor: | Kimberly S. Fuson, Paula M. Robison, Patrick C. May |
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| Rok vydání: | 1999 |
| Předmět: |
Flumazenil
Kainic acid Cell Survival Excitotoxicity Kainate receptor AMPA receptor Biology Pharmacology medicine.disease_cause Hippocampus Receptors N-Methyl-D-Aspartate Neuroprotection Rats Sprague-Dawley Benzodiazepines chemistry.chemical_compound Fetus medicine Animals Receptors AMPA alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid Cells Cultured Neurons Kainic Acid L-Lactate Dehydrogenase General Neuroscience Glutamate receptor Rats Neuroprotective Agents nervous system chemistry NMDA receptor Cyclothiazide Excitatory Amino Acid Antagonists medicine.drug |
| Zdroj: | Neuroscience Letters. 262:219-221 |
| ISSN: | 0304-3940 |
| Popis: | Glutamate excitotoxicity has been implicated in a variety of acute and chronic neurodegenerative diseases but early phase clinical trials with competitive antagonists at both N -methyl- d -aspartate (NMDA)-receptors and α -amino-3-hydroxy-5-methyl-isoxazolepropionate (AMPA) receptors have been disappointing. A family of atypical 2,3 benzodiazepines, exemplified by GYKI 52466, have been described recently which function as non-competitive AMPA-receptor antagonists. We have investigated the neuroprotective efficacy of LY303070 and LY300164, two analogs of GYKI-52466, in an embryonic rat hippocampal culture model of non-NMDA receptor-mediated excitotoxicity using kainic acid (KA) as an agonist at the AMPA/KA receptor. Overnight treatment with 500 μ M KA resulted in prominent neuronal excitotoxicity as assessed by lactate dehydrogenase efflux. LY300164 and LY303070 attenuated KA-excitotoxicity in a dose-dependent manner with IC 50 s of 4 and 2 μ M, respectively. In contrast, their stereoisomers, LY300165 and LY303071 showed no neuroprotection at concentrations up to 25 μ M. In addition, AMPA-mediated excitotoxicity in cyclothiazide pre-treated cultures was also completely blocked by LY303070. Finally, neuroprotection by this class of 2,3 benzodiazepines was not influenced by antagonism of the classical benzodiazepine receptor. LY303070 and LY300164 represent novel non-competitive AMPA-receptor antagonists which may offer unique advantages in the clinic over competitive AMPA-receptor antagonists. |
| Databáze: | OpenAIRE |
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