Autoradiographic Mapping of 5-HT1B1D Binding Sites in the Rhesus Monkey Brain Using [carbonyl-11C]zolmitriptan

Abstract EN

Zolmitriptan is a serotonin 5-HT1B/1D receptor agonist that is an effective and well-tolerated drug for migraine treatment.

In a human positron emission tomography study, [11C]zolmitriptan crossed the blood-brain barrier but no clear pattern of regional uptake was discernable.

The objective of this study was to map the binding of [11C]zolmitriptan in Rhesus monkey brain using whole hemisphere in vitro autoradiography with [11C]zolmitriptan as a radioligand.

In saturation studies, [11C]zolmitriptan showed specific (90%) binding to a population of high-affinity binding sites (Kd 0.95–5.06 nM).

There was regional distribution of binding sites with the highest density in the ventral pallidum, followed by the external globus pallidus, substantia nigra, visual cortex, and nucleus accumbens.

In competitive binding studies with 5-HT1 receptor antagonists, [11C]zolmitriptan binding was blocked by selective 5-HT1B and 5-HT1D ligands in all target areas.

There was no appreciable change in binding with the addition of a 5-HT1A receptor antagonist.