Pretreatment with the 5-HT1A receptor agonists 8-OH-DPAT or gepirone does not attenuate the inhibitory effect of systemically administered cholecystokinin (CCK) on food intake in rats.
In order to investigate whether the inhibitory effect of systemically administered cholecystokinin (CCK) on food intake is dependent on an interaction with central 5-hydroxytryptamine (5-HT) processes, we examined the effects of pretreating rats that were deprived of food for various periods of time (22 h in Experiments 1 and 3, 3 h in Experiment 2, and 1 h in Experiment 4) with the 5-HT1A receptor agonists, 8-OH-DPAT or gepirone, on the suppression of feeding induced by intraperitoneal CCK. 8-OH-DPAT (100 micrograms/kg, Experiments 1 and 2) or gepirone (2 mg/kg, Experiments 3 and 4) administered subcutaneously 60 min prior to intraperitoneal injection of CCK (6 micrograms/kg) did not attenuate the suppressant effect of CCK on feeding in any of these experiments. The 5-HT1A agonists had no significant effects on food intake on their own. As it has been established that the doses of 8-OH-DPAT and gepirone used in this study decrease 5-HT function in the central nervous system, the present results indicate that it is unlikely that the inhibitory effect of systemically administered CCK on food intake is dependent on an interaction with intact central 5-HT systems.
Ebenezer
I S
IS
Neuropharmacology Research Group, School of Pharmacy and Biomedical Sciences, University of Portsmouth, England.
Brooman
J
J
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology*; D000818:Animals; D002766:Cholecystokinin / Q000494:pharmacology*; D003864:Depression, Chemical; D004347:Drug Interactions; D004435:Eating / Q000187:drug effects*; D008297:Male; D011743:Pyrimidines / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*
D011743:Pyrimidines; D017366:Serotonin Receptor Agonists; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D002766:Cholecystokinin; C039979:gepirone