Serotonin modulation of cerebral blood flow measured with positron emission tomography (PET) in humans.
To develop a method to measure the dynamic response of the serotonin system in vivo, the effects of intravenously administered citalopram (the most selective of the serotonin reuptake inhibitors) or clomipramine on cerebral blood flow (CBF) were evaluated. CBF was measured with positron emission tomography (PET) in 27 normal subjects scanned under baseline conditions and, on the same day, after an intravenous (IV) infusion of placebo, citalopram, or clomipramine using a randomized, double-blind design. The main effects of the drugs on blood flow occurred in the thalamus, hypothalamus, and cingulate cortex. Compared to placebo, clomipramine reduced blood flow in the mediodorsal and ventral lateral nuclei of the thalamus, whereas citalopram reduced blood flow in the pulvinar nucleus and the hypothalamus. Compared to clomipramine, citalopram decreased blood flow in the cingulate cortex. The findings support previous reports showing acute central effects of citalopram and clomipramine on regional serotonergic functions measured by PET. Acute side effects may, however, require that care is taken in the selection of experimental designs for future PET studies using IV administration of these antidepressants.
Geday
Jacob
J
PET Center, Aarhus University Hospital, Aarhus, Denmark.
Hermansen
Flemming
F
Rosenberg
Raben
R
Smith
Donald F
DF
D000328:Adult; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging* / Q000187:drug effects* / Q000378:metabolism; D002536:Cerebral Arteries / Q000000981:diagnostic imaging / Q000187:drug effects / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000187:drug effects* / Q000502:physiology; D015283:Citalopram / Q000097:blood / Q000494:pharmacology*; D002997:Clomipramine / Q000097:blood / Q000494:pharmacology*; D004311:Double-Blind Method; D005260:Female; D006179:Gyrus Cinguli / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007031:Hypothalamus / Q000187:drug effects / Q000502:physiology; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D010104:Oxygen Radioisotopes; D049268:Positron-Emission Tomography; D012701:Serotonin / Q000378:metabolism*; D017367:Selective Serotonin Reuptake Inhibitors / Q000097:blood / Q000494:pharmacology; D013788:Thalamus / Q000187:drug effects / Q000502:physiology
D015283:Citalopram; D002997:Clomipramine; D010104:Oxygen Radioisotopes; D012701:Serotonin; D017367:Selective Serotonin Reuptake Inhibitors