title: Blockade action of ketanserin and increasing effect of potassium ion on Kv1.3 channels expressed in Xenopus oocytes.
abstract: The goal of this study was to investigate the pharmacological effects of ketanserin (KT) and elevated extracellular potassium ([K+]o) on Kv1.3 potassium channels. Kv1.3 channels were expressed in Xenopus oocytes, and the resulting currents were measured using a two-microelectrode voltage-clamp technique. KT blocked Kv1.3 currents in a concentration-dependent, time-dependent and voltage-independent manner, and accelerated their activation and inactivation. Kv1.3 currents were increased by high [K+]o in a concentration-dependent manner. Our results suggest that KT acts directly on the open state of the Kv1.3 channel, whereas augmentation of extracellular [K] enhances current flow through the channel by increasing the channel's conductance.
authors.affiliation: Department of Cardiology, Institute of Cardiovascular Diseases, Ion Channelopathy Research Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, PR China. xianpei_wang@163.com
authors.forename: Xianpei
authors.initials: X
authors.lastname: Wang
authors.forename: Yuhua
authors.initials: Y
authors.lastname: Liao
authors.forename: Anruo
authors.initials: A
authors.lastname: Zou
authors.forename: Lu
authors.initials: L
authors.lastname: Li
authors.forename: Danna
authors.initials: D
authors.lastname: Tu
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D006801:Humans; D015640:Ion Channel Gating / Q000187:drug effects*; D007650:Ketanserin / Q000494:pharmacology*; D007700:Kinetics; D051664:Kv1.3 Potassium Channel / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects; D009865:Oocytes; D011188:Potassium / Q000378:metabolism*; D026902:Potassium Channel Blockers / Q000494:pharmacology*; D014982:Xenopus laevis
chemical_list: C496973:KCNA3 protein, human; D051664:Kv1.3 Potassium Channel; D026902:Potassium Channel Blockers; D007650:Ketanserin; D011188:Potassium