| Affiliation: | (1) Department of Virology and Immunology, Institute of Microbiology and Biotechnology, Maria Curie-Sklodowska University, Akademicka 19, 20-033 Lublin, Poland;(2) Department of Toxicology, Institute of Agricultural Medicine, Lublin, Poland;(3) Department of Molecular Medicine, Wakayama Medical University, Wakayama, Japan;(4) Department of Neurotoxicology, Medical Research Centre, Polish Academy of Science, Warsaw, Poland;(5) Department of Pharmacology and Toxicology, Medical University, Lublin, Poland |
| Abstract: | In the present study we demonstrate for the first time that both kynurenine aminotransferase (KAT) isoforms I and II are present in the permanent immature rat oligodendrocytes cell line (OLN-93). Moreover, we provide evidence that OLN-93 cells are able to synthesize kynurenic acid (KYNA) from exogenously added l-kynurenine and we characterize its regulation by extrinsic factors. KYNA production in OLN-93 cells was depressed in the presence of aminotransferase inhibitor, aminooxyacetic acid and was not affected by depolarizing agents such as 50 mM K+ and 4-aminopyridine. Glutamate agonists, l-glutamate and d,l-homocysteine significantly decreased KYNA production. Selective agonist of ionotropic glutamate receptors Amino-2,3-dihydro-5-methyl-3-oxo-4-isoxazolepropionic acid (AMPA) lowered KYNA production in OLN-93 cell line, whereas N-methyl-d-aspartate (NMDA) had no influence on KYNA production. Furthermore, KYNA synthesis in OLN-93 cells was decreased in a concentration-dependent manner by amino acids transported by l-system, l-leucine, l-cysteine and l-tryptophan. The role of KYNA synthesis in oligodendrocytes needs further investigation. |
