Halothane acts as a partial agonist of the alpha6 beta2 gamma2S GABA(A)receptor.

摘要: Whole-cell patch clamp recording was performed on human embryonic kidney 293 cells stably transfected with rat cDNAs for the alpha6, beta2, and gamma2S subunits of GABA(A) receptor. The volatile anesthetic halothane directly activated a current in absence ligand gamma-aminobutyric acid (GABA). Both amplitude rate desensitization increased dose-dependent manner an EC50 1.0+/-0.2 mM Hill coefficient (nh) 1.5+/-0.1. nh GABA to activate receptor were 1.0+/-0.3 microM 1.4+/-0.2, respectively. peak halothane-activated about 4% maximal response, which not changed when concentration Ca2+ external solution decreased from 2 0.2 mM. reversal potential both halothane- GABA-activated currents Cl- as predicted by Nernst equation chloride ions. blocked noncompetitive antagonist picrotoxin competitive bicuculline. Schild plots revealed that K(i)s bicuculline competitively antagonize are similar (0.69 0.72 microM, respectively). These results indicate activates alpha6 beta2 induce GABA-induced current.