Intestinal satiety in rats.

Infusion of liquid food into the duodenum inhibited sham feeding. The inhibition of sham feeding reflected satiety because the duodenal infusion elicited the complete behavioral sequence characteristic of satiety. The chemical and/or colligative load that the infusion imposed on the intestine appeared to be the adequate stimulus for satiety. Duodenal infusions that inhibit sham feeding and elicit satiety are not aversive because they will not function as the unconditioned stimulus for the formation of a conditioned taste aversion for saccharin. We call the satiety elicited by the infusion of food into the duodenum "intestinal satiety." This emphasizes our belief that satiety is a reflex that can be elicited by the activation of receptors in the wall of the intestine. It is known that the activation of some intestinal receptors releases the hormone cholecystokinin (CCK). Since CCK mimics a duodenal infusion by inhibiting sham feeding and eliciting the complete behavioral sequence of satiety, we suggest, but do not prove, that CCK mediates intestinal satiety in the rat.