The 5-HT1A agonist 8-OH-DPAT increases consumption of palatable wet mash and liquid diets in the rat.
The 5-HT1A agonist 8-OH-DPAT, at a dose of 30 micrograms/kg, enhanced the consumption of sweetened wet mash and sweetened milk in non-deprived rats. In partially satiated rats, sensitivity to the hyperphagic effect of 8-OH-DPAT on wet mash intake was substantially increased, so that the minimally effective dose was reduced to 3 micrograms/kg. Similarly, 8-OH-DPAT was more efficacious in increasing milk intake in satiated rats. Thus, 30 and 40 micrograms/kg 8-OH-DPAT produced a 4-fold increase of milk intake in completely satiated rats compared to a 2-fold increase in partially satiated animals at a dose of 30 micrograms/kg. The increased intake of liquid and wet mash diets observed after treatment with low doses of 8-OH-DPAT argues against the involvement of non-specific gnawing in the increased consumption of solid food produced by the drug. Rather, the data suggest that 8-OH-DPAT may specifically stimulate appetite by counteracting a tonic serotonergic inhibition of feeding. The present experiments also showed that 8-OH-DPAT attenuates fenfluramine-induced anorexia which is thought to depend on increased serotonergic neurotransmission.
Dourish
C T
CT
Merck Sharp and Dohme Research Laboratories, Neuroscience Research Centre, Harlow, Essex, UK.
Cooper
S J
SJ
Gilbert
F
F
Coughlan
J
J
Iversen
S D
SD
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D000818:Animals; D004032:Diet; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects*; D005277:Fenfluramine / Q000037:antagonists & inhibitors; D008297:Male; D009281:Naphthalenes / Q000494:pharmacology*; D051381:Rats; D013764:Tetrahydronaphthalenes / Q000494:pharmacology*; D013997:Time Factors
D009281:Naphthalenes; D013764:Tetrahydronaphthalenes; D005277:Fenfluramine; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin