LACK OF INTERACTION BETWEEN DEVAZEPIDE AND 8-OH-DPAT-INDUCED HYPERPHAGIA IN THE RAT

Recently, a number of studies have provided evidence suggesting that C CK and 5-HT interact in the control of food intake. However, the major ity of these studies have relied on the administration of exogenous CC K to investigate potential interactions. The aim of the present study was to focus on the potential role of endogenous CCK in 5-HT-CCK inter actions. Our prediction was that the CCKA antagonist, devazepide, alon e would potentiate the hyperphagic effect of the 5-HT1A agonist, 8-OH- DPAT, in free-feeding rats. The results showed that devazepide, at a d ose that had no intrinsic effect (1.0 mg/kg), did not enhance the hype rphagic effect of 8-OH-DPAT (100 and 300 mu g/kg). This suggests that when serotonergic inhibitory activity is reduced by 5-HT1A-receptor st imulation, there is no compensatory increase of endogenous CCK activit y to excite 5-HT neurons and thereby inhibit food intake. Copyright (C ) 1996 Elsevier Science Inc.