Mesulergine antagonism towards the fluoxetine anti-immobility effect in the forced swimming test in mice.
The anti-immobility effect of fluoxetine (40 mg kg-1) in the forced swimming test in mice was antagonized by the 5-HT1c/2 antagonist mesulergine (7.5 mg kg-1) and the dopamine D2 antagonist (+/-)-sulpiride (12.5 mg kg-1) but not by the 5-HT2/1C antagonist ritanserine (2 mg kg-1), the 5-HT1A/1B antagonist (-)-propranolol (20 mg kg-1) or the 5-HT3 antagonist DAU 6215 (0.1 mg kg-1). All compounds were administered intraperitoneally (i.p.) 6 min before fluoxetine, given i.p. 30 min before testing. The anti-immobility effect of fluoxetine was also prevented by pretreatment with p-chlorophenylalanine (300 mg kg-1 twice daily for 3 days) which produced an 80% reduction of 5-HT in brain. The results suggest that fluoxetine reduces immobility time in mice forced to swim, by acting indirectly through a mesulergine-sensitive site, probably the 5-HT1C receptor.
Cesana
R
R
Boehringer Ingelheim Italia S.p.A., Department of Pharmacology, Milano, Italy.
Ceci
A
A
Ciprandi
C
C
Borsini
F
F
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology; D003863:Depression / Q000188:drug therapy; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004873:Ergolines / Q000494:pharmacology*; D005473:Fluoxetine / Q000037:antagonists & inhibitors*; D007103:Immobilization / Q000502:physiology*; D008297:Male; D051379:Mice; D014179:Neurotransmitter Uptake Inhibitors / Q000494:pharmacology; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology; D013550:Swimming
D004873:Ergolines; D014179:Neurotransmitter Uptake Inhibitors; D011985:Receptors, Serotonin; D005473:Fluoxetine; C031649:mesulergine