Pharmacological Characterization of the Receptor Mediating the Anorexigenic Action of the Octadecaneuropeptide: Evidence for an Endozepinergic Tone Regulating Food Intake

摘要: Peptides of the endozepine family, including diazepam-binding inhibitor, triakontatetraneuropeptide, and octadecaneuropeptide (ODN), act through three types receptors, that is, central-type benzodiazepine receptors (CBR), peripheral-type (mitochondrial) (PBR) a metabotropic receptor positively coupled to phospholipase C via pertussis toxin-sensitive G protein. We have previously reported ODN exerts potent anorexigenic effect in rat we found action is not affected by mixed CBR/PBR agonist diazepam. In present report, tested possible involvement activity ODN. Intracerebroventricular administration C-terminal octapeptide (OP) its head-to-tail cyclic analog cyclo(1-8)OP (cOP) at dose 100 ng mimicked inhibitory on food intake food-deprived mice. The specific CBR antagonist flumazenil PBR PK11195 did prevent ODN, OP, cOP consumption. contrast, selective cyclo(1-8)[DLeu(5)]OP (100-1000 ng; cDLOP) suppressed cOP. At highest concentration (1000 ng), cDLOP provoked itself significant increase intake. Taken together, results indicate OP mediated activation recently characterized astrocytes. data also suggest endogenous acting this receptor, an tone feeding behavior.