Function of GABA rho1 receptors is up-regulated by chronic GABA treatment in Xenopus oocytes.
This study was aimed to investigate the effect of chronic gamma-aminobutyric acid (GABA) treatment on homomeric GABA rho1 receptors expressed in Xenopus oocytes. The rho1 mRNA-injected oocytes were incubated with 10 mM GABA for 2, 6, 24, 48 or 72 h, prior to the assessment of GABA-gated ion currents. The results showed that GABA exposure for more than 6 h dramatically enhanced the peak GABA-activated currents. In addition to current amplitude, the apparent GABA potency and cooperativity were significantly increased. The enhancement reached its plateau after a 24-h exposure. The up-regulation of GABA current amplitude was completely inhibited by cycloheximide, a translation inhibitor. This suggests that chronic GABA treatment may increase the translational activity of GABA rho1 subunit in Xenopus oocytes.
Lin
L H
LH
Department of Pharmacology, Chang Gung University School of Medicine, Kweisan, Taoyuan, Taiwan. lhlin@mcw.edu
Din
T S
TS
Pan
Y L
YL
D000818:Animals; D003513:Cycloheximide / Q000494:pharmacology; D004553:Electric Conductivity; D005260:Female; D007536:Isomerism; D009865:Oocytes / Q000187:drug effects* / Q000378:metabolism* / Q000502:physiology; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D018079:Receptors, GABA / Q000187:drug effects / Q000378:metabolism*; D013997:Time Factors; D015854:Up-Regulation / Q000502:physiology*; D014981:Xenopus; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D011500:Protein Synthesis Inhibitors; D018079:Receptors, GABA; D005680:gamma-Aminobutyric Acid; D003513:Cycloheximide