Endogenous cholecystokinin (CCK) is thought to participate in the satiating action of foods, and some data suggest that it may also mediate their postingestive reinforcing effects. This was investigated by determining if the CCK(A) receptor antagonist, devazepide, attenuates flavor preference conditioning by intraduodenal (I.D.) carbohydrate infusions. In Experiment 1, food-restricted female rats were trained 30 min/day to associate a cue flavor (CS+) with I.D. infusions of 8% Polycose and a different flavor (CS ) with I.D. water infusions. Half of the rats (DEV group) were pretreated with devazepide (300 microg/kg body weight) and the other half (CON group) with vehicle, 30 min prior to CS training sessions and choice tests. Both groups displayed similar CS+ preferences (CON: 68%; DEV: 69%). In contrast, devazepide blocked the feeding inhibitory effects of I.D. Polycose infusion and cholecystokinin octapeptide injection in Experiment 2. A higher dose of devazepide (1200 microg/kg) also failed to inhibit preference conditioning by I.D. Polycose in Experiment 3. These results indicate that, although CCK(A) mechanisms play a role in the satiating effect of I.D. carbohydrates, they do not mediate their reinforcing effect. The present study, along with other recent reports, indicate that different mechanisms mediate the satiating and reinforcing actions of nutrients.