Wa. Cass et al., EFFECTS OF NEUROTOXIC DOSES OF METHAMPHETAMINE ON POTASSIUM AND AMPHETAMINE EVOKED OVERFLOW OF DOPAMINE IN THE STRIATUM OF AWAKE RATS, Neuroscience letters, 248(3), 1998, pp. 175-178
The effects of neurotoxic doses of methamphetamine on basal and evoked
overflow of dopamine in the striatum were examined in awake rats usin
g microdialysis. Male Fischer-344 rats were administered methamphetami
ne (5 mg/kg s.c.) or saline four times in 1 day at 2-h intervals. Micr
odialysis experiments were carried out 1 week later. Basal levels of d
opamine, 3,4-dihydroxyphenylacetic acid, and homovanillic acid were re
duced in the striatum of the methamphetamine-treated animals. Local ap
plication of excess potassium (100 mM) and amphetamine (100 mu M), and
intraperitoneal injection of amphetamine (1.5 mg/kg), led to increase
d levels of extracellular dopamine in the striatum of both methampheta
mine- and saline-treated rats. However, the increase was significantly
less in the methamphetamine-treated animals. Tissue levels of dopamin
e and metabolites were reduced in the striata of rats treated with met
hamphetamine. These results indicate that treatment with neurotoxic do
ses of methamphetamine can lead to functional changes in dopamine rele
ase in the striatum of Fischer-344 rats. (C) 1998 Published by Elsevie
r Science Ireland Ltd. Ail rights reserved.