LESION OF THE AREA POSTREMA NUCLEUS OF THE SOLITARY TRACT (AP NTS) ATTENUATES THE ANORECTIC EFFECTS OF AMYLIN AND CALCITONIN-GENE-RELATED PEPTIDE (CGRP) IN RATS/

The area postrema/nucleus of the solitary tract (AP/NTS) region plays an important role in the control of food intake since it receives peri pheral satiety signals via splanchnic and vagal afferents. Due to the lack of the blood brain barrier in this region, blood borne signals ca n directly be monitored in the AP/NTS. Furthermore, receptors for anor ectic peptides such as amylin or calcitonin gene-related peptide (CGRP ) have been found in the AP/NTS. It was therefore the aim of the prese nt study to investigate the role of the AP/NTS region in mediating the anorectic effects of these peptides. Thermal ablation of the AP/NTS r esulted in a significant reduction of the anorectic effects of IP inje cted amylin (5 mu g/kg) and CGRP (5 mu g/kg) in food deprived rats. Th e anorectic actions of CCK and BBS were also reduced by the AP/NTS les ion which agrees with previous studies. We conclude that the AP/NTS re gion is an important brain site for mediating the anorectic effects of amylin and CGRP. It remains to be clarified whether this effect is du e to amylin and CGRP action on receptors within the AP/NTS region or p eripheral receptors on afferent nerves projecting to the AP/NTS. (C) 1 998 Elsevier Science Inc.