Cholecystokinin: induced suppression of feeding in fed, fasting and hypothalamic island rats.

Experiments were undertaken to examine the involvement of CCK in the regulation of feeding behavior. The results indicate that 1) intact normal animals exhibited rhythmic circadian feeding behavior, with onset of feedings starting about two hr prior to dark period and continuing until 1 to 2 hr prior to the light period; 2) food deprivation and surgical isolation of the hypothalamus after this pattern of feeding behavior, to the point that animals spend more time eating with no identifiable pattern; 3) administration of CCK to either fed, fasted or hypothalamic island animals has a profound dose related effect on suppressing feeding behavior and in modifying the eating pattern over 24 hr. A possible involvement of CCK with the opiate system in controlling feeding behavior is discussed.