INTERACTION OF CCK AND 8-OH-DPAT IN THE SATIATION OF ALCOHOL INTAKE

Administration of the neuropeptide cholecystokinin (CCK) is known to r educe food and alcohol intake and preference. The food satiation effec t of CCK is reportedly dependent on serotonergic neurotransmission. Ad ministration of 8-OH-DPAT, a serotonin(1A) autoreceptor agonist, reduc es the ability of CCK to inhibit feeding. We determined if CCK's alcoh ol satiation effect also depends on activity of serotonergic neurons b y administering 8-OH-DPAT (120-240 mu g/kg) to 23-h water-deprived fem ale and male rats, followed 1 h later by IP injection of CCK (4 mu g/k g) and 30-min access to 5% w/v ethanol. 8-OH-DPAT significantly (p < 0 .05) interacted with CCK, and reduced CCK's ethanol satiation effect w hen given IP but increased CCK's effect when given SC. Female rats sho wed this interaction of 8-OH-DPAT with CCK at a higher dose than males when given IF, but females were more sensitive to SC 8-OH-DPAT's abil ity to reduce ethanol intake. Results are consistent with previous fin dings of dose-, sex-, and route-dependent biphasic effects of 8-OH-DPA T on feeding and ethanol intake. A partial dependence of CCK's alcohol satiation effect on serotonergic neurotransmission is revealed in thi s design. (C) 1998 Elsevier Science Inc.