The neuronal NOS inhibitor L-MIN, but not 7-NINA, reduces neurotoxic effects of chronic intrastriatal administration of quinolinic acid

Abstract Rat striata were exposed to 15 mM quinolinic acid (QUIN), or QUIN plus the nitric oxide synthase inhibitors S -methyl- l -thiocitrulline dihydrochloride ( l -MIN) or 7-nitroindazole monosodium salt (7-NINA) for 21 days. Co-administration of 100 μ M or 1 mM l -MIN with QUIN significantly reduced lesion volume compared to QUIN alone. Co-administration of 1 μ M or 10 μ M l -MIN with QUIN had no significant effect. There was no significant effect of 7-NINA co-administered with QUIN compared to QUIN alone. l -MIN reduction of lesion volume supports the contention that neuronal nitric oxide synthase is a mediator of excitotoxic injury.