Effect of one-week ethanol treatment on monoamine levels and dopaminergic receptors in rat striatum
Braz. j. med. biol. res
;
36(4): 503-509, Apr. 2003. tab, graf
Article
in English
| LILACS
| ID: lil-331234
RESUMO
We studied the effects of ethanol on the levels of norepinephrine, dopamine, serotonin (5-HT) and their metabolites as well as on D1- and D2-like receptors in the rat striatum. Ethanol (2 or 4 g/kg, po) was administered daily by gavage to male Wistar rats and on the 7th day, 30 min or 48 h after drug administration, the striatum was dissected for biochemical assays. Monoamine and metabolite concentrations were measured by HPLC and D1- and D2-like receptor densities were determined by binding assays. Scatchard analyses showed decreases of 30 and 43 percent, respectively, in D1- and D2-like receptor densities and no change in dissociation constants (Kd) 48 h after the withdrawal of the dose of 4 g/kg. Ethanol, 2 g/kg, was effective only on the density of D2-like receptors but not on Kd of either receptor. Thirty minutes after the last ethanol injection (4 g/kg), decreases of D2 receptor density (45 percent) as well as of Kd values (34 percent) were detected. However, there was no significant effect on D1-like receptor density and a 46 percent decrease was observed in Kd. An increase in dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC), a decrease in norepinephrine, and no alteration in 5-HT levels were demonstrated after 48-h withdrawal of 4 g/kg ethanol. Similar effects were observed in dopamine and DOPAC levels 30 min after drug administration. No alteration in norepinephrine concentration and a decrease in 5-HT levels were seen 30 min after ethanol (4 g/kg) administration. Our findings indicate the involvement of the monoaminergic system in the responses to ethanol
Full text:
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Index:
LILACS (Americas)
Main subject:
Receptors, Dopamine D2
/
Receptors, Dopamine D1
/
Corpus Striatum
Limits:
Animals
/
Humans
/
Male
Language:
English
Journal:
Braz. j. med. biol. res
Journal subject:
Biology
/
Medicine
Year:
2003
Type:
Article
Affiliation country:
Brazil
Institution/Affiliation country:
Universidade Federal do Ceará/BR
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