EFFECT OF PYLORIC CUFFS ON CHOLECYSTOKININ SATIETY

Because inflation of a pyloric cuff during feeding blocks gastric empt ying and increases gastric distention, this device was used to test th e hypothesis of synergism between gastric distention and cholecystokin in octapeptide (CCK-8) in reducing intake. Adult, male Sprague-Dawley rats were allowed 20-min access to 30% sucrose, with or without inflat ion of pyloric cuffs, after intraperitoneal injection of saline or 1, 2, or 4 mu g/kg CCK-8. Cuff inflation resulted in large increases in g astric volume at the end of feeding tests. However, this manipulation failed to enhance the effectiveness of any dose of CCK-8. In fact, dat a analyses revealed trends suggestive of decreased effectiveness of th e two lowest doses under these conditions. The effect of 4 mu g/kg CCK -8 was almost identical in tests with and without cuff inflation. Thes e results are contrary to the prediction of greater potency of CdK-8 r esulting from increased gastric distention.