INTRACEREBROVENTRICULAR INJECTION OF CCK REDUCES OPERANT SUGAR INTAKEIN PIGS

Pigs have a strong appetite for sugar solutions and readily learn to p erform operant responses (pressing a panel with their snouts) to obtai n glucose solution. Intracerebroventricular (ICV) injection of 1 mu g CCK produced a significant (p < 0.01) reduction in the amount of gluco se consumed compared with saline in the 30 min following injection. Th e reduction was a central effect as the same dose of CCK was ineffecti ve given intravenously. The inhibition of intake was completely abolis hed by prior dosing with 100 mu g of the CCKA receptor antagonist Deva zepide given ICV. Devazepide itself had no effect on intake. The pig i s a good experimental animal for the study of the regulation of sugar intake.