Abdominal vagotomy decreases the satiating potency of CCK-8 in sham and real feeding.

To compare the effect of total abdominal vagotomy on the satiating potency of cholecystokinin COOH-terminal octapeptide (CCK-8) in sham feeding and real feeding, we administered CCK-8 intraperitoneally (2, 4, and 8 micrograms/kg) 1 min before a sham feeding or real feeding intake test. CCK-8 was at least as potent for inhibiting intake during sham feeding as it was during real feeding. Total abdominal vagotomy decreased the satiating potency of all three doses of CCK-8 equally in both feeding conditions. These results are consistent with the proposal that abdominal vagal afferent fibers are as necessary for the mediation of the satiating effect of CCK-8 in sham feeding as they are in real feeding.