Immediate and "day-after" effects of morphine on dopamine and serotonin metabolism in various structures of the rat brain.
The effects of a single dose of 20 mg/kg ip of morphine on dopaminergic and serotonergic systems in the limbic (cortex, nucleus accumbens) and extrapyramidal (striatum) structures were investigated in rats. The action of morphine was assessed by measuring the regional concentrations of dopamine, serotonin and their metabolites (homovanillic acid- HVA,3,4-dihydroxyphenylacetic acid - DOPAC, 5-hydroxyindoleacetic acid - 5-HIAA) by means of HPLC. We have demonstrated that a single large dose of morphine produces a biphasic change in limbic dopaminergic and serotonergic structures, with an initial activation followed by significant inhibition 24 h later. In contrast, the striatum depression of dopamine level was observed during the initial phase with normalization on the next day.
Antkiewicz-Michaluk
L
L
Department of Biochemistry, Polish Academy of Sciences, Kraków, Poland.
Romańska
I
I
Vetulani
J
J
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism*; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000378:metabolism*; D013997:Time Factors
D015102:3,4-Dihydroxyphenylacetic Acid; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D009020:Morphine; D004298:Dopamine