quinolate metabolism PMID:15206762 metabolism of quinolinate (quinolinic acid), a potent endogenous excitotoxin of neuronal cells. Elevation of quinolinate levels in the brain has been implicated in the pathogenesis of various neurodegenerative disorders, the so-called 'quinolinate hypothesis.' Quinolinate is non- enzymatically derived from alpha-amino-beta-carboxymuconate-epsilon- semialdehyde (ACMS). ACMS decarboxylase (ACMSD) is the only known enzyme that can process ACMS to a begnin catabolite and thus prevent the accumulation of quinolinate from ACMS. ACMSD seems to be regulated by nutritional and hormonal signals, but its molecular mechanism has, to date, been largely unknown. [PMID:12140278]. UPa:UPA00270 PMID:12140278 pathway PMID:17288562 quinolinic acid metabolism secondary metabolite metabolism