What is "raclopride"

n. A synthetic compound that acts as an antagonist on D2 dopamine receptors.

Raclopride is a synthetic compound that acts as a selective antagonist on D dopamine receptors.

Its selectivity to the cerebral D receptors is characterized by its respective K-values, which are as follows: 1.8, 3.5, 2400 and 18000 nM for D, D, D and D receptors respectively.

It can be radiolabelled with radioisotopes, e.g. H or C and used as a tracer for in vitro imaging (autoradiography) as well as in vivo imaging positron emission tomography (PET). Images obtained by cerebral PET scanning (e.g. PET/CT or PET/MRI) allow the non-invasive assessment of the binding capacity of the cerebral D dopamine receptor, which can be useful for the diagnosis of movement disorders. In particular, cerebral D receptor binding as measured by carbon-11-raclopride (C-raclopride) has shown to reflect disease severity of Huntington's disease, a genetical disease characterized by selective degeneration of cerebral D receptors.

Other studies have investigated the relationship of D receptor binding capacity and personality disorders. For example, one study found decreasing binding with the personality trait detachment. Radiolabelled raclopride is also commonly used to determine the efficacy and neurotoxicity of dopaminergic drugs.