Decreased expression of kynurenine aminotransferase-I (KAT-I) in the substantia nigra of mice after 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment
| Autor: | Beáta Krisztin-Péva, Bertalan Csillik, Elizabeth Knyihár-Csillik, M Pákáski, Etsuo Okuno, László Vécsei, E. Dobó |
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| Rok vydání: | 2004 |
| Předmět: |
Male
medicine.medical_specialty Time Factors Tyrosine 3-Monooxygenase Blotting Western Dopamine Agents Cell Count Substantia nigra Biology Gene Expression Regulation Enzymologic Mice chemistry.chemical_compound Kynurenic acid Dopamine Internal medicine Glial Fibrillary Acidic Protein medicine Animals Neurotoxin Microscopy Immunoelectron Transaminases Neurons CD11b Antigen Tyrosine hydroxylase Pars compacta General Neuroscience MPTP Dopaminergic Immunohistochemistry Mice Inbred C57BL Substantia Nigra Endocrinology nervous system chemistry 1-Methyl-4-phenyl-1 2 3 6-tetrahydropyridine Female Microglia medicine.drug |
| Zdroj: | Neuroscience. 126:899-914 |
| ISSN: | 0306-4522 |
| Popis: | Nerve cells in the substantia nigra pars compacta (SNPC) are known to express tyrosine hydroxylase (TH). By means of light and electron microscopical immunohistochemical techniques, we have shown that the dopaminergic neurons of SNPC express also kynurenine aminotransferase (KAT-I), the enzyme taking part in the formation of kynurenic acid, a neuroprotectant which is one of the endogeneous antagonists of N-methyl-d-aspartate receptors. It was also found that microglial cells and astrocytes express KAT-I. It has been shown that the highly selective dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), widely used as a model of Parkinson's disease (PD), affects not only TH of dopaminergic neurons in the SNPC but also their KAT-I immunoreactivity as well: MPTP treatment decreased the number and optical density of KAT-I immunoreactive SNPC neurons. Decrease of KAT-I after MPTP treatment has been proved also by Western blot analysis. MPTP also reduced KAT-I immunoreactivity of microglial cells, except for those involved in reactive gliosis, which were arranged in groups surrounding affected neurons of the SNPC; also the number of KAT-I immunoreactive (IR) astroglial cells was increased in SNPC. We conclude that MPTP treatment may have a dual effect: in addition to being deleterious for neurons expressing TH and KAT-I, it also affects glial cells which could exacerbate the neurodegenerative process characterizing PD. |
| Databáze: | OpenAIRE |
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