L-DOPA does not facilitate nitric oxide production in the rat striatum and substantia nigra: in vivo microdialysis study.
Using in vivo microdialysis and flow-injection, we evaluated the production of nitric oxide (NO) in the striatum and substantia nigra of freely moving rats in response to challenge doses of L-dihydroxyphenylalanine (L-DOPA) by measuring the NO metabolite levels of nitrate and nitrite. The dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) concentrations also were determined in the same perfusates. Intraperitoneal injection of L-DOPA produced a significant, dose-dependent increase in the extracellular levels of dopamine and DOPAC in these areas, but did not modify the extracellular levels of the NO metabolites. An acute dose of L-DOPA does not appear to facilitate NO production in the rat striatum and substantia nigra.
Department of Neurology, Okayama University Medical School, Japan. kkashi@cc.okayama-u.ac.jp
K
K
Kashihara
K
K
Sakai
K
K
Marui
T
T
Shohmori
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D005110:Extracellular Space / Q000378:metabolism; D007980:Levodopa / Q000494:pharmacology*; D008297:Male; D017551:Microdialysis; D009569:Nitric Oxide / Q000096:biosynthesis* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013378:Substantia Nigra / Q000187:drug effects* / Q000378:metabolism
D015102:3,4-Dihydroxyphenylacetic Acid; D009569:Nitric Oxide; D007980:Levodopa; D004298:Dopamine