W. Dyr et al., EFFECTS OF D1 AND D2 DOPAMINE RECEPTOR AGENTS ON ETHANOL-CONSUMPTION IN THE HIGH-ALCOHOL-DRINKING (HAD) LINE OF RATS, Alcohol, 10(3), 1993, pp. 207-212
Dopamine receptor agonists and antagonists were tested for effects on
alcohol drinking in female HAD rats (n = 10) given limited access (4 h
/day) to a 10% (v/v) ethanol solution. Food and water were available a
d libitum. Subcutaneous drug injections were given 30-60 min before th
e ethanol access periods. The D2 agonist quinpirole (0.04-2.0 mg/kg) c
aused a dose-dependent decrease in alcohol drinking throughout the 4-h
period. Spiperone, a D2 antagonist, had no effect during the initial
part of the session, but by the fourth hour, the 10 mug/kg dose tended
to increase alcohol intake and the 30 mug/kg dose reduced intake. The
D1 antagonist SCH-23390 (3-30 mug/kg) dose-dependently decreased etha
nol drinking during the first hour of access. The D1 agonist SKF-38393
(2-6 mg/kg) also decreased alcohol intake, but it was less effective
than SCH-23390. The findings implicate both D1 and D2 receptors in the
reinforcing effects of alcohol drinking by the HAD line of rats.