Dietary quinine has a nongustatory effect on food intake in rats

Recent data suggests that quinine adulteration of rats' maintenance diets may suppress food intake by postingestional (i.e., pharmacological or toxicological) mechanisms. This possibility was tested by increasing rats' rates of drug excretion prior to presentation of quinine maintenance diets. This treatment increased consumption of 3 concentrations (0.1, 0.2, 0.4%) of quinine diet in 2 separate experiments. In a third experiment, the same treatment did not alter consumption of quinine water in a 2 bottle test, suggesting that the increased consumption of quinine adulterated food was not due to a generalized decrease in the gustatory aversiveness of quinine. The data directly support the idea that quinine has postingestional effects which account for at least part of the suppression of food intake seen with quinine adulterated diets. The data further suggest that at least some of these effects occur postabsorptively.