%0 Journal Article %A D J Henry %A D K Grandy %A H A Lester %A N Davidson %A C Chavkin %T Kappa-opioid receptors couple to inwardly rectifying potassium channels when coexpressed by Xenopus oocytes. %D 1995 %J Molecular Pharmacology %P 551-557 %V 47 %N 3 %X 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. %U https://molpharm.aspetjournals.org/content/molpharm/47/3/551.full.pdf