title: A proton-activated, outwardly rectifying chloride channel in human umbilical vein endothelial cells.
abstract: Extracellular acidic pH-activated chloride channel I(Cl, acid), has been characterized in HEK 293 cells and mammalian cardiac myocytes. This study was designed to characterize I(Cl,acid) in human umbilical vein endothelial cells(HUVECs). The activation and deactivation of the current rapidly and repeatedly follows the change of the extracellular solution at pH 4.3, with the threshold pH 5.3. In addition, at very positive potentials, the current displays a time-dependent facilitation. pH-response relationship for I(Cl,acid) revealed that EC(50) is pH 4.764 with a threshold pH value of pH 5.3 and nH of 14.545. The current can be blocked by the Cl(-) channel inhibitor DIDS (100 microM). In summary, for the first time we report the presence of proton-activated, outwardly rectifying chloride channel in HUVECs. Because an acidic environment can develop in local myocardium under pathological conditions such as myocardial ischemia, I(Cl,acid) would play a role in regulation of EC function under these pathological conditions.
authors.affiliation: Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Public Health, Department of Cardiology QiLu Hospital Shandong University, West Wenhua Road 107, Jinan 250012, China.
authors.forename: Zhi-Yong
authors.initials: ZY
authors.lastname: Ma
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Liang
authors.initials: L
authors.lastname: Chen
authors.forename: Rong
authors.initials: R
authors.lastname: Wang
authors.forename: Xiao-Hong
authors.initials: XH
authors.lastname: Kan
authors.forename: Gui-Zhen
authors.initials: GZ
authors.lastname: Sun
authors.forename: Chun-Xi
authors.initials: CX
authors.lastname: Liu
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000494:pharmacology; D000143:Acids / Q000494:pharmacology*; D002460:Cell Line; D002478:Cells, Cultured; D065101:Chloride Channel Agonists; D018118:Chloride Channels / Q000037:antagonists & inhibitors; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D014471:Umbilical Veins / Q000166:cytology
chemical_list: D000143:Acids; D065101:Chloride Channel Agonists; D018118:Chloride Channels; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid