[Hokkaido igaku zasshi] The Hokkaido journal of medical science
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Hokkaido Igaku Zasshi · Jan 1997
[Experimental study of methamphetamine psychosis--role of glutamate and nitric oxide in methamphetamine-induced dopaminergic and serotonergic neurotoxicity in the rat brain].
The present study examined effects of a high dose of methamphetamine (MA) (5mg/kg, s.c., x 4) on extracellular concentrations of dopamine (DA), dihydroxyphenylacetic acid (DOPAC), 5-hydroxyindoleacetic acid (5-HIAA) and glutamate in rat striatum (ST) and nucleus accumbens (NA) using microdialysis. The toxic dose of MA markedly increased extracellular DA, and decreased DOPAC and 5-HIAA in both ST and NA. The increase in DA release was not different in magnitude between ST and NA. ⋯ Taking into account the relationship between NMDA receptor activation and NO formation, the present study examined effects of a NO synthesis inhibitor, N omega-nitro-L-arginine methyl ester (LNAME) on MA-induced decreases in contents of the monoamines and their metabolites, in order to clarify whether the MA-induced dopaminergic and serotonergic neurotoxicity would be mediated by NO synthesis. Coadministration with LNAME (30 mg/kg, i.p., x2), reduced the MA-induced decreases in contents of DA, DOPAC and HVA in ST, but not reduced the MA-induced decreases in contents of 5-HT in ST and NA. These findings suggest that the MA-induced dopaminergic, but not serotonergic neurotoxicity, may be related to the neural process such as NO formation caused by the activation of postsynaptic DA receptor.