[125I]LSD labels 5-HT1C recognition sites in pig choroid plexus membranes. Comparison with [3H]mesulergine and [3H]5-HT binding

Abstract The mammalian choroid plexus is enriched in a newly described serotonin recognition site, the 5-HT 1C site. In order to further characterize these sites, the binding characteristics of [ 125 I]LSD, [ 3 H]mesulergine and [ 3 H]serotonin to pig choroid plexus membranes were compared. These ligands labelled with high affinity a similar number of sites. The binding profiles of the sites labelled with these radioligands are indistinguishable as illustrated by highly significant correlation parameters. These sites are very similar to those labelled by N 1 -methyl-2-[ 125 I]LSD and [ 125 I]LSD in pig and rat choroid plexus membranes. The data demonstrate that these ligands label 5-HT 1C recognition sites in pig and rat choroid plexus membranes.