Referenced in: none

Automatically associated channels: Kv1.3 , Slo1

Title: Open channel block of Kv1.3 by rosiglitazone and troglitazone: Kv1.3 as the pharmacological target for rosiglitazone.

Authors: Hye Sook Ahn, Sung Eun Kim, Hyun-Jong Jang, Myung-Jun Kim, Duck-Joo Rhie, Shin-Hee Yoon, Yang-Hyeok Jo, Myung-Suk Kim, Ki-Wug Sung, Seong Yun Kim, Sang June Hahn

Journal, date & volume: Naunyn Schmiedebergs Arch. Pharmacol., 2007 Jan , 374, 305-9

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/17119927

Abstract
The effects of rosiglitazone and troglitazone were examined on cloned Kv1.3 channels stably expressed in Chinese hamster ovary cells using the whole-cell configuration of the patch-clamp technique. Rosiglitazone decreased the Kv1.3 currents and accelerated the decay rate of current inactivation in a concentration-dependent manner with an IC(50) of 18.6 microM. These effects were reversible after washout of the drug. Troglitazone caused the block of Kv1.3 with a similar pattern but was five times more potent than rosiglitazone with an IC(50) of 3.5 microM. The block of Kv1.3 by rosiglitazone and troglitazone was voltage-dependent at a membrane potential coinciding with the activation of the channels. Both drugs decreased the tail current amplitude and slowed the deactivation process of Kv1.3, resulting in a tail crossover phenomenon. These results indicate that rosiglitazone and troglitazone block the open state of Kv1.3 channels, suggesting that it is an important pharmacological target for rosiglitazone as a potent blocker of Kv1.3 channels.