Role of zinc in blockade of excitotoxic action of quinolinic acid by picolinic acid.

This study examined whether picolinic acid (PIC) inhibits quinolinic acid (QUIN)-induced excitotoxicity through zinc chelation. Injection of QUIN into the nucleus basalis magnocellularis significantly depleted cortical choline acetyltransferase activity 7 days post injection and PIC inhibited this response. Zinc augmented the QUIN- but not NMDA-induced response. When PIC was co-administered with zinc, PIC failed to attenuate the QUIN-induced response. The inhibition of QUIN-induced cholinergic toxicity by PIC may involve chelation of zinc.