Ethanol intake of chickens treated with fenfluramine, fluoxetine, and dietary tryptophan.
Male, white leghorn chickens fed a standard diet with or without tryptophan supplementation were treated with single injections of 8 mg/kg fenfluramine in one series of experiments, or 8 mg/kg fluoxetine in another series. The birds had been food- and water-deprived prior to injection. They were offered, following the drug or saline injection, water, a 5% ethanol solution, or an isocaloric sucrose solution (8.75%) for 1 hr. Both fluoxetine and fenfluramine significantly reduced consumption of the ethanol solution, an effect exacerbated by tryptophan supplementation. Water or sucrose solution intake was also significantly reduced, but significantly less so than ethanol after fenfluramine injection. Since the birds drank significantly more of the sucrose solution after saline injection than of water, the consumption decrease caused by fenfluramine resulted, nevertheless, in a higher intake than that of either water or ethanol. Body temperature was decreased by ethanol intake and/or fluoxetine injection. Fenfluramine injection had an opposite, body temperature-increasing effect. It appears that both fenfluramine and fluoxetine decrease ethanol intake in a manner more specific than for water or sucrose, and that this effect is amplified by dietary tryptophan supplementation.