[3H]paroxetine and [3H]citalopram as markers of the human brain 5-HT uptake site: a comparison study.
The binding of [3H]paroxetine and [3H]citalopram to the human brain serotonin (5-HT) uptake site has been characterized and compared. Our results reveal that the binding exclusively involved with the 5-HT uptake site is identical for both [3H]ligands. The selective 5-HT uptake inhibitor citalopram displays the highest affinity for this uptake site, as compared with the affinities obtained for desipramine and norzimeldine, which is in accordance with their respective blockage of 5-HT uptake. Similar Bmax values were obtained for both radioligands in the brain regions studied, indicating their binding to the same presynaptic membrane protein. Together these findings suggest that both [3H]paroxetine and [3H]citalopram are good markers of the 5-HT transporter as both bind selectively and with high affinity to the serotonin uptake sites. However, the higher affinity of [3H]paroxetine confirms that this compound is the best radioligand for the 5-HT uptake site available today.
Arranz
B
B
Department of Geriatric Medicine, University of Linköping, Sweden.
Marcusson
J
J
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects; D015415:Biomarkers; D001923:Brain Chemistry / Q000187:drug effects*; D015283:Citalopram / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008566:Membranes / Q000187:drug effects / Q000378:metabolism; D008875:Middle Aged; D017374:Paroxetine / Q000493:pharmacokinetics; D051381:Rats; D011985:Receptors, Serotonin / Q000187:drug effects*
D015415:Biomarkers; D011985:Receptors, Serotonin; D015283:Citalopram; D017374:Paroxetine