Changes in kynurenic, anthranilic, and quinolinic acid concentrations in rat brain tissue during development

Kynurenic, anthranilic, and quinolinic acid, brain tissue concentrations an d indoleamine 2,3-dioxygenase [EC 1 13.11.17] activity were determined in r at brain, during pre- and postnatal development. Quinolinic acid brain tiss ue concentration was significantly increased at birth as compared with the prenatal level, then it declined rapidly in the postnatal period. By the co ntrary, kynurenic and anthranilic acids brain tissue concentrations in rat brain were significantly lower at birth as compared with those found prenat ally; then kynurenic acid concentration decreased in the first postnatal we ek and increased thereafter, while anthranilic acid concentration increased in the first postnatal week and decreased thereafter, Indoleamine 2,3-diox ygenase [EC 1 13.11.17] activity were found unchanged in pre and post natal rat brain. The described opposite changes in quinolinic and kynurenic acid s concentrations, occurring in pre- and postnatal period, despite the lack of knowledge on the precise role played by these compounds on the different neurotransmitter systems in the brain, could be involved in brain ontogene tic development.