Regional effects of sodium valproate on extracellular concentrations of 5-hydroxytryptamine, dopamine, and their metabolites in the rat brain: an in vivo microdialysis study.
The effects of sodium valproate (VPA; 100, 200, and 400 mg/kg, i.p.) on ventral hippocampal and anterior caudate putamen extracellular levels of dopamine (DA) and 5-hydroxytryptamine (5-HT) were examined using in vivo microdialysis. VPA induced dose-related increases in dialysate DA, 3,4-dihydroxyphenylacetic acid, and 5-HT in the ventral hippocampus. Anterior caudate putamen dialysate 5-HT was also dose dependently elevated by the drug, whereas DA levels tended to decrease with increasing VPA dose. In contrast, VPA (200, 400, and 800 mg/kg, i.p.) produced no significant elevation of DA in posterior caudate putamen dialysates, although 5-HT levels were significantly elevated at the 400- and 800-mg/kg doses. In all three regions studied, dialysate concentrations of 5-hydroxyindoleacetic acid and homovanillic acid remained at basal levels following VPA treatments. The results are discussed with regard to the possible anticonvulsant mode of action of VPA.
Biggs
C S
CS
Department of Pharmacology, School of Pharmacy, London, England, U.K.
Pearce
B R
BR
Fowler
L J
LJ
Whitton
P S
PS
D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects*; D003956:Dialysis; D004298:Dopamine / Q000378:metabolism*; D005110:Extracellular Space / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D006624:Hippocampus / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D008297:Male; D011699:Putamen / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000378:metabolism*; D014635:Valproic Acid / Q000494:pharmacology*
D012701:Serotonin; D014635:Valproic Acid; D004298:Dopamine