title: The inhibitory effect of curcumin on voltage-dependent K⁺ channels in rabbit coronary arterial smooth muscle cells.
abstract: We investigated the effects of curcumin, the principal active compound of turmeric, on voltage-dependent K(+) (Kv) channels in freshly isolated rabbit coronary arterial smooth muscle cells using the voltage-clamp technique. Curcumin reduced the Kv current in a dose-dependent manner with an apparent K(d) value of 1.07 ± 0.03 μM. Although curcumin did not alter the kinetics of Kv current activation, it predominantly accelerated the decay rate of channel inactivation. The association and dissociation rate constants of curcumin were 1.35 ± 0.05 μM(-1)s(-1) and 1.47 ± 0.17s(-1), respectively. Curcumin did not alter the steady-state activation or inactivation curves. Application of train pulses (1 or 2 Hz) increased curcumin-induced blockade of the Kv current, and the recovery time constant also increased in the presence of curcumin suggesting, that the inhibitory action of Kv currents by curcumin was use-dependent. From these results, we concluded that curcumin inhibited vascular Kv current in a state-, time-, and use-dependent manner.
authors.affiliation: Department of Physiology, Kangwon National University School of Medicine, 1 Kangwondaehak-gil, Chuncheon 200-701, South Korea.
authors.forename: Da Hye
authors.initials: DH
authors.lastname: Hong
authors.forename: Youn Kyoung
authors.initials: YK
authors.lastname: Son
authors.forename: Il-Whan
authors.initials: IW
authors.lastname: Choi
authors.forename: Won Sun
authors.initials: WS
authors.lastname: Park
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003331:Coronary Vessels / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D003474:Curcumin / Q000494:pharmacology*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000187:drug effects* / Q000378:metabolism; D024642:Potassium Channels, Voltage-Gated / Q000037:antagonists & inhibitors*; D011817:Rabbits
chemical_list: D024642:Potassium Channels, Voltage-Gated; D003474:Curcumin