104104-50-9

0.2 μM (GABA receptor).

Both bicuculline and Gabazine (SR 95531) have been characterized as competitive inhibitors of GABA binding to the GABA _A receptor. Gabazine is more potent than bicuculline at blocking currents elicited by GABA, with an IC ₅₀ for currents elicited by 3 μM GABA of ~0.2 μM and a Hill coefficient of 1.0. Gabazine reduces the currents elicited by 10 μM alphaxalone by ~30%, for responses of receptors containing wildtype β2 subunits. The concentration of Gabazine requires producing half the maximal block is ~0.2 μM. Gabazine also could only produce a partial block of currents gated by 300 μM pentobarbital. The maximal reduction, again, is ~30%, and the concentration of Gabazine required to produce half the maximal block is ~0.15 μM.