J Pharm Pharmacol 2013 Sep 01;659:1321-8. doi: 10.1111/jphp.12095.

Blockade of the human ether-a-go-go-related gene potassium channel by ketamine.

???displayArticle.abstract???
The inhibition of the cardiac rapid delayed rectifier potassium current (IKr ) and its cloned equivalent human ether-a-go-go-related gene (hERG) channel illustrate QT interval prolonging effects of a wide range of clinically used drugs. In this study, the direct interaction of the intravenous anaesthetic ketamine with wild-type (WT) and mutation hERG currents (IhERG ) was investigated.The hERG channel (WT, Y652A and F656A) was expressed in Xenopus oocytes and studied using standard two-microelectrode voltage-clamp techniques.WT hERG is blocked in a concentration-dependent manner with IC50  = 12.05 ± 1.38 μm by ketamine, and the steady-state inactivation curves are shifted to more negative potentials (about -27 mV). The mutation to Ala of Y652 and F656 located on the S6 domain attenuate IhERG blockade by ketamine, and produced approximately 9-fold and 2.5-fold increases in IC50 compared with that of WT hERG channel, respectively.Ketamine blocks WT IhERG expressed in Xenopus oocytes in a concentration-dependent manner and predominantly interacts with the open hERG channels. The interaction of ketamine with hERG channel may involve the aromatic residues Tyr652 and Phe656.

???displayArticle.pubmedLink??? 23927470
???displayArticle.link??? J Pharm Pharmacol


Species referenced: Xenopus
Genes referenced: gnao1 kcnh1 kcnh2