RT Journal Article
SR Electronic
T1 Kappa-opioid receptors couple to inwardly rectifying potassium channels when coexpressed by Xenopus oocytes.
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP 551
OP 557
VO 47
IS 3
A1 Henry, D J
A1 Grandy, D K
A1 Lester, H A
A1 Davidson, N
A1 Chavkin, C
YR 1995
UL http://molpharm.aspetjournals.org/content/47/3/551.abstract
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.