FLUOXETINE REDUCES SACCHARIN-INDUCED ELEVATION OF FLUID INTAKE IN ALCOHOL-PREFERRING FAWN-HOODED RATS

Previous work has established that saccharin and alcohol intakes are h ighly correlated in a variety of rat strains. In addition, it has been shown that alcohol-preferring rats consume saccharin beyond the limit of their normal daily fluid intake (DFI). Tt has been hypothesized th at alcohol-preferring rats have impaired control over consumption of r einforcing substances, which may be related to a deficiency of brain s erotonin. In the present study, we examined the effect of the serotoni n reuptake inhibitor fluoxetine (2.5, 5.0, 10.0 mg/kg, IP, twice a day ) on saccharin intake in alcohol-preferring Fawn-Hooded (FH) rats. It was confirmed that alcohol preferring FH rats almost triple their DFI when saccharin/water choice was introduced. Treatment with fluoxetine resulted in a dose-dependent decrease in saccharin intake to, but not below, the normal level of their DFI. No significant effects of fluoxe tine on water intake were observed. Despite a significant (up to 69%) decrease in saccharin intake, only a minimal reduction (<4%) in saccha rin preference occurred. We conclude that fluoxetine reduces the exess ive elevation of fluid intake observed at the presence of the palatabl e saccharin solution in Fawn-Hooded rats. These findings may provide m ore evidence for the involvement of the serotonergic system in the bra in in exessive drinking of rewarding substances. (C) 1997 Elsevier Sci ence Inc.