THE EFFECTS OF CENTRAL ADMINISTRATION OF THE CCK-B RECEPTOR AGONIST PENTAGASTRIN ON FEEDING AND CORTISOL RELEASE IN SHEEP

In order to test the validity of the hypothesis that implicates centra l cholecystokinin-B (CCK-B) receptors in the etiology of anxiety and p anic disorders, we argued that activation of these receptors by the CC K-B receptor agonist pentagastrin should (i) suppress feeding in hungr y animals, and (ii) increase plasma concentrations of the stress hormo ne cortisol. We found that intracerebroventricular administration of p entagastrin (4 and 10 mu g) did not inhibit feeding nor increase corti sol secretion in sheep (n = 6). Moreover, the peptide did not produce behavioral responses in the animals. We conclude that central CCK-B re ceptors are unlikely to be involved in behaviors associated with anxie ty or panic in this species.