ECV304内皮细胞株的钙激活非选择性阳离子通道及肿瘤坏死因子-α的抑制作用  

Calcium Activated Non-selective Cation Channel in Endothelial Cell Line ECV304 and Inhibition of Tumor Necrosis Factor－α

作　　者：鲍光宏[1] 于德洁[1] 林琳[1] 郑永芳[1] 

机构地区：[1]中国医学科学院中国协和医科大学基础医学研究所生物物理研究室,北京100005

出　　处：《中国医学科学院学报》2000年第5期449-453,共5页Acta Academiae Medicinae Sinicae

基　　金：国家自然科学基金重点项目!( 39730220)资助

摘　　要：目的 研究人脐静脉内皮细胞株 ECV304的钙激活非选择性阳离子通道的特征和肿瘤坏死因子-α (TNF-α )对该通道的调控作用。方法 膜片箝细胞贴附式单通道和全细胞方式记录通道活动。结果 内皮细胞膜的单通道活动可被钙离子激活，通道电导γ =(19.74± 2.35)pS(n=7)，通道平均开放概率 Po=0.260± 0.006(n=5)。通道活动可被 TNF-α抑制，表现为通道电导和开放概率降低，分别为γ 1=(10.69± 4.68)pS(n=5)， Po1=0.230± 0.050(n=5)。用膜片箝的全细胞记录所得结果与单通道记录一致。通道活动还可被氯通道阻断剂蒽 9羧酸 (Anthracene-9-Carboxylic acid, A9C)显著地抑制，将电极液中的 KCl和 NaCl用 K-Aspartate置换，电极液不含氯离子，也记录到单通道活动。其单通道电导为 (18.33± 2.98)pS(n=8)，通道活动也能被 TNF-α和 A9C所抑制，但不能被另一氯通道阻断剂 ZnSO4所抑制。又置换 K-Aspartate为 CsCl未记录到未置换溶液前的结果。 Cs＋难以通过此通道，提示所记录到的通道活动不是钙激活氯通道 ICl(Ca)，而是钙激活非选择性阳离子通道。结论 内皮细胞株 ECV304的非选择性阳离子通道可被肿瘤坏死因子 TNF-α和 A9C所抑制。Objective To study the character of non-selective cation channel in human umblical cord vein endothelial cell line ECV304 and the effect of tumor necrosis factor－α (TNF-α ) on channel activity. Method Patch clamp technique was used to record single channel and whole cell currents. Results This channel can be activated by calcium , channel conductance was (19.74± 2.35)pS and its Po was 0.260± 0.006(n=5).100U/ml TNF-α inhibited channel activity,showing that conductance reduced to (10.69± 4.68)pS and Po reduced to 0.230± 0.051 (n=5). Results in whole-cell configuration were consistent with that in cell-attached patches. Currents were obviously blocked by Cl- channel inhibitor anthracere-9-carboxylic acid (A9C). In order to testify the character of this channel further, KCl and NaCl were exchanged by K＋-Asparate in pipette solution. Under this condition, the single channel activities as before were recorded again. Its conductance was (18.33± 2.98)pS(n=8), and TNF－α as well as A9C could inhibit channel activity. But this channel activity could not be blocked by another Cl- channel blocker Zn2＋ . In the condition of K-Asparate replaced by CsCl in solution, identical channel activity as before could not be recorded. It seemed that Cs＋ could not pass through this cation channel. Conclusion It is inferred that calcium-activated non-selectivecation channel recorded in endothelial cell ECV304, can be inhibited by TNF－α and A9C.

关 键 词：内皮细胞 ECV304 肿瘤坏死因子-Α CAN 抑制作用 

分 类 号：R322.123[医药卫生—人体解剖和组织胚胎学]