DEVAZEPIDE, A CCKA ANTAGONIST, ATTENUATES THE SATIATING BUT NOT THE PREFERENCE CONDITIONING EFFECTS OF INTESTINAL CARBOHYDRATE INFUSIONS INRATS

Endogenous cholecystokinin (CCK) is thought to participate in the sati ating action of foods, and some data suggest that it may also mediate their postingestive reinforcing effects. This was investigated by dete rmining if the CCKA receptor antagonist, devazepide, attenuates flavor preference conditioning by intraduodenal (ID) carbohydrate infusions. In Experiment 1, food-restricted female rats were trained 30 min/day to associate a cue flavor (CS+) with ID infusions of 8% Polycose and a different flavor (CS-) with ID water infusions. Half of the rats (DEV group) were pretreated with devazepide (300 mu g/kg body weight) and the other half (CON group) with vehicle, 30 min prior to CS training s essions and choice tests. Both groups displayed similar CS+ preference s (CON: 68%; DEV: 69%). In contrast, devazepide blocked the feeding in hibitory effects of ID Polycose infusion and cholecystokinin octapepti de injection in Experiment 2. A higher dose of devazepide (1200 mu g/k g) also failed to inhibit preference conditioning by ID Polycose in Ex periment?. These results indicate that, although CCKA mechanisms play a role in the satiating effect of ID carbohydrates, they do not mediat e their reinforcing effect. The present study, along with other recent reports, indicate that different mechanisms mediate the satiating and reinforcing actions of nutrients. (C) 1998 Elsevier Science Inc.