Premium
Cerebrosides of baifuzi, a novel potential blocker of calcium‐activated chloride channels in rat pulmonary artery smooth muscle cells
Author(s) -
Gao Shangbang,
Wang Changming,
Chen Xuesong,
Yu Weiwei,
Mo Biwen,
Li Chenhong
Publication year - 2007
Publication title -
cell biology international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.932
H-Index - 77
eISSN - 1095-8355
pISSN - 1065-6995
DOI - 10.1016/j.cellbi.2007.02.005
Subject(s) - chloride channel , depolarization , chemistry , pipette , biophysics , channel blocker , vascular smooth muscle , smooth muscle , membrane potential , calcium , niflumic acid , patch clamp , biochemistry , medicine , biology , receptor , organic chemistry
Calcium‐activated chloride channels (CaCCs) are crucial regulators of vascular tone by promoting a depolarizing influence on the resting membrane potential of vascular smooth muscle cells. However, the lack of a special blocker of CaCCs has limited the investigation of its functions for long time. Here, we report that CB is a novel potential blocker of I Cl(Ca) in rat pulmonary artery smooth muscle cells (PASMC). Cerebrosides (CB) were isolated from Baifuzi which is dried root tuber of the herb Typhonium giganteum Engl used for treatment of stroke in traditionalmedicine. Using the voltage‐clamp technique, sustained Ca 2+ ‐activatedCl − current ( I Cl(Ca) ) was evoked by a K + ‐free pipette solution containing 500 nM Ca 2+ which exhibited typical outwardly rectifying and voltage‐/time‐dependence characterization. Data showed that CB played a distinct inhibitory role in modulating the CaCCs. Moreover, we investigated the kinetic effect of CB on I Cl(Ca) and found that it could slow the activation dynamics of the outward current, accelerate the decay of the inward tail current and change the time‐dependence characterization. We conclude that CB is a novel potent blocker of CaCCs. The interaction between CB and CaCCs is discussed.