Fenfluramine administered systemically or locally increases extracellular serotonin in the lateral hypothalamus as measured by microdialysis.
Microdialysis was used to monitor serotonin, 5-hydroxyindoleacetic acid (5-HIAA) and the metabolites of dopamine, dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the perifornical lateral hypothalamus (PFH) of freely moving rats. Systemically administered d-fenfluramine (d-FEN) increased extracellular serotonin, DOPAC and HVA, while decreasing serotonin's metabolite 5-HIAA. Local application of d-FEN directly to the hypothalamic terminal region caused large increases in extracellular serotonin and had a tendency to decrease all 3 metabolites. This effect was confirmed when d-FEN was infused locally by reverse dialysis. These results provide direct evidence that the anorectic drug d-FEN can increase extracellular serotonin in the hypothalamus in vivo and suggest a serotonergic action in the perifornical region. This finding is consistent with our report that a meal also increases serotonin in this region.
Schwartz
D
D
Department of Psychology, Princeton University, NJ 08544.
Hernandez
L
L
Hoebel
B G
BG
D000818:Animals; D004298:Dopamine / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005110:Extracellular Space / Q000378:metabolism*; D005277:Fenfluramine / Q000008:administration & dosage*; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D007026:Hypothalamic Area, Lateral / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008845:Microinjections; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism*; D013997:Time Factors
D005277:Fenfluramine; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D004298:Dopamine