FUNCTIONAL EXPRESSION OF GABA RHO-3 RECEPTORS IN XENOPUS OOCYTES

Homomeric rat GABA rho 3 receptors were expressed in Xenopus oocytes, and their pharmacological profile was investigated electrophysiologica lly. GABA activated the rho 3 receptors with an EC(50) value of 7.5 mu M and a Hill coefficient of 1.6. The GABA-induced current was not ant agonized by bicuculline (100 mu M), but was blocked by picrotoxin (IC5 0: 0.68 mu M for 100 mu M GABA). The current was almost insensitive to pentobarbital, diazepam and a neurosteroid, 3 alpha-OH-DHP. Many of t he pharmacological properties of the rho 3 subunit were similar to tho se of the previously reported rat rho 1 and rho 2 subunits and GABA(C) receptors. Copyright (C) 1996 Elsevier Science Ireland Ltd