Bodilisant-A Novel Fluorescent, Highly Affine Histamine H3 Receptor Ligand

A piperidine-based lead structure for the human histamine H-3 receptor (hH(3)R) was coupled with the BODIPY fluorophore and resulted in a strong green fluorescent (quantum yield, 0.92) hH(3)R ligand with affinity in the nanomolar concentration range (K-i hH(3)R = 6.51 +/- 3.31 nM), named Bodilisant. Screening for affinities at histamine and dopamine receptor subtypes showed high hH(3)R preference. Bodilisant was used for visualization of hH(3)R in hH(3)R overexpressing HEK-293 cells with fluorescence confocal laser scanning microscopy. In addition, in native human brain tissues, Bodilisant showed clear and displaceable images of labeled hH(3)R.