PET measurement of the influence of corticosteroids on serotonin-1A receptor number.
BACKGROUND
The hypothalamic-pituitary-adrenal (HPA) axis and serotonergic system interact functionally. The modulatory effect of corticosteroids on 5-HT(1A) receptor number and function has been repeatedly demonstrated in preclinical studies suggesting that raised corticosteroid levels decrease 5-HT(1A) receptor number and function in the hippocampus.


METHODS
We used positron emission tomography (PET) to quantify the number of 5-HT(1A) receptors in two studies, the first in normal subjects given a single dose of hydrocortisone using a random-order, double-blind, placebo-controlled design and second in patients treated long-term with corticosteroids.


RESULTS
We did not find that exposure to elevated levels of corticosteroids in either the short or long term alters 5-HT(1A) receptor binding in the hippocampus or other brain regions examined.


CONCLUSIONS
This study does not support the hypothesis that corticosteroids exert a major inhibitory regulatory control over the 5-HT(1A) receptor binding in the human brain.
Montgomery
A J
AJ
MRC Cyclotron Unit, Imperial College School of Medicine, Charing Cross Hospital, St. Dunstans Road, United Kingdom, London.
Bench
C J
CJ
Young
A H
AH
Hammers
A
A
Gunn
R N
RN
Bhagwagar
Z
Z
Grasby
P M
PM
D000328:Adult; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D001667:Binding, Competitive; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D006624:Hippocampus / Q000033:anatomy & histology / Q000378:metabolism; D006801:Humans; D006854:Hydrocortisone / Q000008:administration & dosage / Q000493:pharmacokinetics*; D007030:Hypothalamo-Hypophyseal System / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010913:Pituitary-Adrenal System / Q000378:metabolism*; D011985:Receptors, Serotonin / Q000378:metabolism*; D044263:Receptors, Serotonin, 5-HT1; D014055:Tomography, Emission-Computed
D000893:Anti-Inflammatory Agents; D011985:Receptors, Serotonin; D044263:Receptors, Serotonin, 5-HT1; D006854:Hydrocortisone