Extracellular 5-hydroxytryptamine concentration in rat hypothalamus after administration of fluoxetine plus L-5-hydroxytryptophan.
Fluoxetine (10 mg kg-1, i.p.) caused a three- to fourfold increase in extracellular 5-hydroxytryptamine (5-HT) concentration measured by microdialysis in hypothalamus of freely moving rats. The addition of L-5-hydroxytryptophan at 20 or 40 mg kg-1, i.p. doses, magnified the increase in extracellular 5-HT to as much as 16 times basal levels, although these doses of L-5-hydroxytryptophan alone had only small effects on extracellular 5-HT. The increased formation of 5-HT following L-5-hydroxytryptophan administration appears to overcome homeostatic mechanisms that limit the increases in extracellular 5-HT caused by uptake inhibition.
Perry
K W
KW
Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285.
Fuller
R W
RW
D006916:5-Hydroxytryptophan / Q000494:pharmacology*; D000818:Animals; D003956:Dialysis; D004305:Dose-Response Relationship, Drug; D005110:Extracellular Space / Q000378:metabolism; D005473:Fluoxetine / Q000494:pharmacology*; D007031:Hypothalamus / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000378:metabolism*
D005473:Fluoxetine; D012701:Serotonin; D006916:5-Hydroxytryptophan