PT - JOURNAL ARTICLE AU - D J Henry AU - D K Grandy AU - H A Lester AU - N Davidson AU - C Chavkin TI - Kappa-opioid receptors couple to inwardly rectifying potassium channels when coexpressed by Xenopus oocytes. DP - 1995 Mar 01 TA - Molecular Pharmacology PG - 551--557 VI - 47 IP - 3 4099 - http://molpharm.aspetjournals.org/content/47/3/551.short 4100 - http://molpharm.aspetjournals.org/content/47/3/551.full SO - Mol Pharmacol1995 Mar 01; 47 AB - Xenopus oocytes expressed kappa-opioid specific binding sites after injection of cRNA prepared from a clone of the rat kappa-opioid receptor. Coinjection of kappa receptor cRNA with cRNA coding for a G protein-linked, inwardly rectifying, K+ channel (GIRK1, or KGA) resulted in oocytes that responded to the kappa agonist U-69593 by activating a large (1.0-1.5-microA) K+ current. U-69593 exhibited an EC50 of 260 +/- 50 nM and was blocked by the opioid antagonists norbinaltorphimine and naloxone. The kappa agonist bremazocine was 200-fold more potent than U-69593 in eliciting K+ current but exhibited a partial agonist profile in this expression system. The present results indicate that stimulation of inwardly rectifying K+ channels may be a potential effector mechanism for kappa-opioid receptors.