L-dopa pretreatment potentiates striatal dopamine overflow and produces dopamine terminal injury after a single methamphetamine injection.
Rats receiving L-dopa/carbidopa (70 mg/kg/17.5 mg/kg, i.p.) 1 h prior to a single methamphetamine (m-AMPH) (4 mg/kg, s.c.) pretreatment showed an extraordinary striatal dopamine (DA) overflow into the extracellular space (30-60 times basal overflow) as compared to the DA overflow elicited by m-AMPH alone (4-5 times basal). Animals treated with L-dopa/carbidopa plus m-AMPH, but not m-AMPH alone, had substantial (60%) decreases in striatal DA content 1 week later. These findings support the conclusion that the magnitude of m-AMPH-induced DA overflow contributes to the degree of nerve terminal damage and highlight the importance of extracellular DA in striatal terminal damage.
Weihmuller
F B
FB
Department of Psychobiology, University of California, Irvine 92717.
O'Dell
S J
SJ
Marshall
J F
JF
D000704:Analysis of Variance; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003342:Corpus Striatum / Q000378:metabolism*; D003956:Dialysis; D004298:Dopamine / Q000378:metabolism*; D004357:Drug Synergism; D004563:Electrochemistry; D007267:Injections; D007980:Levodopa / Q000008:administration & dosage* / Q000494:pharmacology; D008297:Male; D008694:Methamphetamine / Q000494:pharmacology*; D009411:Nerve Endings / Q000187:drug effects* / Q000378:metabolism*; D009420:Nervous System / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley
D008694:Methamphetamine; D007980:Levodopa; D004298:Dopamine