Type A CCK receptors mediate satiety effects of intestinal nutrients

Previous work indicates chat endogenous CCK mediates suppression of sham feeding by some intraintestinal nutrients. To test whether the mechanism involved is dependent upon action at type A or type B CCK receptors, we examined the ability of CCKA (devazepide) and CCKB (L-365,260) receptor antagonists to attenuate the suppression of sham feeding by intraintestinal oleic acid, maltotriose, or L-phenylalanine. Suppression by oleic acid or maltotriose was dose dependently attenuated by intraperitoneal administration of the CCKA receptor antagonist, as was suppression by exogenous CCK. The CCB receptor antagonist failed to attenuate the suppression of sham feeding by these nutrients. Neither receptor antagonist attenuated the suppression of sham feeding induced by intraintestinal L-phenylalanine. These results suggest that suppression of sham feeding by intestinally infused oleic acid and maltotriose is mediated by endogenous CCK acting at CCKA receptors.