Involvement of central gastrin and cholecystokinin in the regulation of food intake in the neonatal chick

The effects of intracerebroventricular (ICV) injection of chicken gastrin a nd cholecystokinin (CCK) on food intake were compared in the neonatal chick . In Experiment 1, the effect of 131 pmol of chicken gastrin (36 amino acid residues) on food intake was compared with 66 and 131 pmoL of CCK-8S over 2h. Chicken gastrin strongly inhibited food intake, but both levels of CCK- 8S did not, The similar effect of 131 pmol chicken gastrin was obtained by 262 pmoL CCK-8S at Ih after ICV injection in Experiment 2. This suppressive effect of chicken gastrin continued over 2h after ICV injection though the effect of CCK-8S had disappeared by 2h. In. Experiment 3, the effects of 1 31 pmol of CCK- 8S, CCK-33S and chicken gastrin were compared. The effect o f CCK-8S was weak, but CCK-33S and chicken gastrin similarly and strongly i nhibited food intake of chicks. These results suggested that the suppressiv e effect of food intake of gastrin /CCK family may be dependent upon the le ngth of amino acid sequence.