EFFECT OF CHOLECYSTOKININ ON MEAL SIZE AND INTERMEAL INTERVAL IN SHAM-FEEDING RAT

Gave 8 Sprague-Dawley male albino rats with gastric fistulas liquid food with the fistula closed (normal feeding) or open (sham feeding) after 3 hrs of food deprivation. Meal size (MS) was larger, latency to rest (LR) after a meal was longer, and intermeal interval (IMI) was shorter during sham feeding than during normal feeding. The putative satiety signal cholecystokinin (CCK, 20% pure) decreased MS and LR and increased IMI during sham feeding. After CCK (30 U/kg) the MS, LR, and IMI were the same during sham feeding as during normal feeding. The synthetic octapeptide (OCT) of CCK, which has the known biological actions of the complete hormone, reproduced the effects of CCK (30 U/kg) on MS and LR but not on IMI. The CCK and OCT were also tested for their ability to serve as a UCS for the formation of a conditioned taste aversion (CTA) in 10 3-hr food-deprived sham-feeding rats. The OCT did not serve as a UCS for a CTA in the same sham-feeding conditions in which OCT produced normal MS and LR. Impure CCK (30 U/kg), however, did serve as a UCS for a CTA under these conditions. Results are consistent with the hypothesis that CCK produces satiety in rats. (18 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1978 American Psychological Association.