Reduced ethanol consumption during cyproheptadine administration in rats from a long-term alcohol-treated colony.

The influence of cyproheptadine (CPH) on forced and voluntary ethanol intake was studied in long-term alcohol-treated rats. Wistar rats from a colony (WAC) that have been drinking alcohol as their only liquid fluid for the 25 previous generations and from a genetically related colony (WN) that had never been given alcohol were used. In the first experiment, daily IP doses of 15 mg/kg CPH were found to reduce forced ethanol consumption during CPH treatment in both WAC and WN rats which had been drinking ethanol for six months. In two additional groups of WAC and WN rats which were not given ethanol, water intake was not affected by CPH administration. In a second experiment, alcohol preference was reduced both during and after CPH, but total fluid intake (ethanol + water) was not affected. These findings suggest that the effect of CPH could be specific to ethanol. The decrease in ethanol consumption was associated with a significant body weight loss; this result may support the hypothesis of a link between the serotoninergic system, food intake, and alcohol drinking behavior that has been considered by earlier investigators.