Referenced in: none

Automatically associated channels: Kir2.1 , Kir3.1

Title: Kappa-opioid receptors couple to inwardly rectifying potassium channels when coexpressed by Xenopus oocytes.

Authors: D J Henry, D K Grandy, H A Lester, N Davidson, C Chavkin

Journal, date & volume: Mol. Pharmacol., 1995 Mar , 47, 551-7

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/7700253

Abstract
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.