Receptor Occupancy (RO) / Receptor Autoradiogarphy
Tests used for CNS drug development such as receptor autoradiography, ex vivo and in vivo receptor occupancy (RO) offer a simple yet powerful way to:
- Determine the tissue distributions of target of interest.
- Obtain Ki values by displacement assay on brain slices. (Figure 1)
- Monitor the interaction of drug candidates with their targets in the brain after peripheral administration to select best leads and eliminate inferior compounds. A drug candidate has to be potent and possess good ‘drug-like’ properties to achieve significant brain occupancy of its target. (Figure 2)
- Better understand the pharmacokinetic and pharmacodynamic relationships of a drug candidate. Ex vivo RO can be used to better understand the percentage of receptor occupancy required for behavioral efficacy. (Figure 2)
Beta-imaging technology, developed by Biospace, France, and used by scientists at PsychoGenics, significantly shortens the time needed for assessment of specific binding in the brain (hours versus weeks for tritiated ligands), which makes it possible to use ex vivo RO (an assay that could provide crucially important preclinical data for preclinical and clinical candidate selection) as a screening tool.
Currently, we have developed protocols for ex vivo receptor occupancy and receptor autoradiography studies for the following targets.
RO_list of targets
Histology / Immunohistochemistry
Microdialysis / Bioanalysis
Molecular Biology & Pharmacology