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Different mechanisms of glutamate‐induced neuronal death between dopaminergic and non‐dopaminergic neurons in rat mesencephalic culture
Author(s) -
Sawada H.,
Kawamura T.,
Shimohama S.,
Akaike A.,
Kimura J.
Publication year - 1996
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/(sici)1097-4547(19960215)43:4<503::aid-jnr12>3.0.co;2-2
Subject(s) - dopaminergic , neurotoxicity , glutamate receptor , dopamine , neuroscience , chemistry , pharmacology , biology , biochemistry , toxicity , receptor , organic chemistry
Parkinson's disease is characterized by dopaminergic neuronal degeneration, but its pathogenic mechanism is still unknown. In the dopaminergic neurons, oxygen radicals such as hydrogen peroxide are released through dopamine oxidation. Many factors are involved in radical formation, but glutamate and nitric oxide (NO) are the major effectors of the radical‐induced neurotoxicity mediated primarily through calcium influx. In the cultured embryonic rat mesencephalon, we investigated the dopaminergic and non‐dopaminergic neuronal death induced by glutamate and by NO‐generating agents. Although glutamate had a neurotoxic effect on both dopaminergic and non‐dopaminergic neurons, it showed slightly greater effect in the dopaminergic neurons. In contrast to glutamate, NO‐generating agents (S‐nitrosocysteine and sodium nitroprusside) showed neurotoxic effects restricted exclusively to non‐dopaminergic neurons. Although N o ‐nitro‐L‐arginine, an NO synthase inhibitor, had no significant effect on the glutamate‐induced cytotoxicity in dopaminergic neurons, it had a significant antagonistic effect on that in non‐dopaminergic neurons. These findings indicate the presence of two different mechanisms of glutamate‐induced neuronal death, one being neurotoxicity not mediated by NO, found in dopaminergic neurons, and the other being that mediated via NO, found in non‐dopaminergic neurons. © 1996 Wiley‐Liss, Inc.