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 electrophysiologically. GABA activated the rho 3 receptors with an EC50 value of 7.5 microM and a Hill coefficient of 1.6. The GABA-induced current was not antagonized by bicuculline (100 microM), but was blocked by picrotoxin (IC50: 0.68 microM for 100 microM GABA). The current was almost insensitive to pentobarbital, diazepam and a neurosteroid, 3 alpha-OH-DHP. Many of the pharmacological properties of the rho 3 subunit were similar to those of the previously reported rat rho 1 and rho 2 subunits and GABAC receptors.
Shingai
R
R
Department of Information Science, Faculty of Engineering, Iwate University, Morioka, Japan. shingai@cis.iwate-u.ac.jp
Yanagi
K
K
Fukushima
T
T
Sakata
K
K
Ogurusu
T
T
D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D009865:Oocytes / Q000187:drug effects; D010852:Picrotoxin / Q000494:pharmacology*; D018079:Receptors, GABA / Q000187:drug effects*; D014982:Xenopus laevis; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D010852:Picrotoxin; D018079:Receptors, GABA; D005680:gamma-Aminobutyric Acid