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

A piperidine-based lead structure for the human histamine H₃ receptor (hH₃R) was coupled with the BODIPY fluorophore and resulted in a strong green fluorescent (quantum yield, 0.92) hH₃R ligand with affinity in the nanomolar concentration range (<i>K</i>_i hH₃R = 6.51 ± 3.31 nM), named Bodilisant. Screening for affinities at histamine and dopamine receptor subtypes showed high hH₃R preference. Bodilisant was used for visualization of hH₃R in hH₃R 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 hH₃R