Vagotomy does not alter cholecystokinin's inhibition of sham feeding

Verified bilateral abdominal vagotomy (with hepatic branch intact) did not alter the ability of 20% pure cholecystokinin (CCK) or octapeptide of cholecystokinin (CCK-8) to inhibit sham feeding of liquid diet in dose-response studies for male Sprague-Dawley rats with open gastric fistula. In light of previous reports that 1) abdominal vagotomy blocks the satiety effect of exogenous CCK-8 on real feeding in intact rats and 2) inhibition of sham feeding requires seemingly supraphysiological doses of exogenous CCK or CCK-8, these findings show that the inhibition of sham feeding by CCK and the inhibition of real feeding by CCK are different. This limits the utility of the sham-feeding preparation for examining mechanisms for the satiety action of CCK.