Intake of dietary sucrose or fat reduces amphetamine drinking in rats

Abstract

The effects of intake of a palatable food source on oral amphetamine intake were assessed in adult male Long-Evans rats. In Experiment 1, six rats were given an amphetamine sulfate solution (0.1 mg/ml) and four rats were given water as their sole source of fluid. Rats were given a choice of chow and granulated sucrose for a week, alternated with weeks when only chow was fed. In Experiment 2, eight rats were given the amphetamine solution, and four rats water to drink. Rats were fed chow and hydrogenated vegetable fat for a week alternated with weeks when only chow was available. In both experiments, rats drank significantly less of the amphetamine solution when the palatable food choice was available than when given only chow to eat. Intake of palatable foods had a significantly smaller effect on water intake. In both experiments, rats drinking the amphetamine solution took in less fluid and less calories and gained less weight than rats drinking water. However, in Experiment 1, when sucrose was available, rats drinking amphetamine consumed a significantly greater proportion of their calories as sucrose than rats drinking water. Similarly, in Experiment 2, rats drinking the amphetamine solution chose a significantly greater percentage of their calories as fat than rats drinking water. These results demonstrate that intake of sucrose or fat leads to a significant reduction in amphetamine intake, and that the anorectic effects of amphetamine are not equivalent for different types of foods.