Quinolinic acid inhibits glutamate uptake into synaptic vesicles from rat brain

Quinolinic acid (QA) is an endogenous and potent neurotoxin associated with the neurotoxicity of various common diseases. The uptake of neurotransmitt ers into synaptic vesicles is an important event involved in the storage an d release of neurotransmitters by vesicles. The influence of QA on the upta ke of glutamate, GABA and glycine into rat brain synaptic vesicles was inve stigated. QA (0.3-10 mM) significantly inhibited (>50%) the uptake of gluta mate into synaptic vesicles, whereas QA at concentrations up to 10 mM had n o significant effect on GABA or glycine uptake. Such results indicate that QA is able to selectively inhibit the vesicular uptake of glutamate, withou t interfering with the uptake of the inhibitory neurotransmitters GABA and glycine. These findings might be related to the neurotoxic effects of QA in the brain. NeuroReport 11:249-253 (C) 2000 Lippincott Williams & Wilkins.