Increase in extracellular serotonin produced by uptake inhibitors is enhanced after chronic treatment with fluoxetine.
The effect of prolonged uptake inhibition with fluoxetine (10 mg/kg/day i.p. x 14 days) on extracellular serotonin (5-HT) in the rat diencephalon was monitored using in vivo microdialysis. The increase in extracellular 5-HT after repeated administration of fluoxetine was significantly greater than the increase produced by a single injection of this uptake blocker. This difference may have been due to a decrease in somatodendritic autoreceptor sensitivity, since the response to a low dose of the 5-HT1A agonist 8-OH-DPAT (25 micrograms/kg i.v.) was abolished in the chronic rats, while the response to a high dose (100 micrograms/kg i.v.) was attenuated as compared to animals injected once with fluoxetine.
Rutter
J J
JJ
Department of Biological Sciences, Rutgers University, Piscataway, NJ 08855.
Gundlah
C
C
Auerbach
S B
SB
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000818:Animals; D004027:Diencephalon / Q000187:drug effects / Q000378:metabolism; D004594:Electrophysiology; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D005473:Fluoxetine / Q000494:pharmacology*; D008297:Male; D017551:Microdialysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000378:metabolism*; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology*
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D005473:Fluoxetine; D012701:Serotonin; D017367:Selective Serotonin Reuptake Inhibitors