Ro 04-5595 free base

Ro 04-5595 is a selective antagonist of NMDA receptors NR2B subunits. Ro 04-5595 had an EC 50 of 186 ± 32 nmol/L. Ro 04-5595 was predicted to bind the EVT-101 binding site, not the ifenprodil-binding site. Specific binding, defined with a new NR2B-specific antagonist Ro 04-5595 at 10 microM was fully inhibited by several compounds with the following rank order of affinities--Ro 25-6981 > CP-101,606 > Ro 04-5595 = ifenprodil >> eliprodil > haloperidol > spermine > spermidine > MgCl2 > CaCl2--and partially inhibited by competitive glutamate recognition site antagonists. Complementary high-resolution autoradiographic images using [3H]Ro04-5595 demonstrated strong binding in NR2B receptor-rich regions and low binding in cerebellum where NR2B concentration is low.