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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 characteristics of calcium-activated nonselective cation channels in human umbilical vein endothelial cell line ECV304 and the regulation of tumor necrosis factor-α (TNF-α) on this channel. Methods Patch clamp cells were attached to single-channel and whole-cell recording channel activity. Results The single channel activity of endothelial cell membrane was activated by Ca2+. The channel conductance was γ = (19.74 ± 2.35) pS (n = 7). The average open probability of the channel was Po = 0.260 ± 0.006 (n = 5). Channel activity was inhibited by TNF-α, which showed a decrease in channel conductance and open probability, γ 1 = (10.69 ± 4.68) pS (n = 5) and Po 1 = 0.230 ± 0.050 (n = 5), respectively. Whole-cell recordings using patch clamps were consistent with single-channel recordings. The channel activity was also significantly inhibited by the chloride channel blocker Anthracene-9-Carboxylic acid (A9C). KCl and NaCl in the electrode solution were replaced by K-Aspartate, and the electrode solution did not contain chloride ions. Record single channel activity. The single-channel conductance was (18.33± 2.98) pS (n=8). The channel activity was also inhibited by TNF-α and A9C, but it could not be inhibited by another chloride channel blocker, ZnSO4. K-Aspartate was replaced by the result that CsCl was not recorded before the solution was replaced. Cs+ is difficult to pass through this channel, suggesting that the recorded channel activity is not calcium-activated chloride channel ICl (Ca), but calcium-activated nonselective cation channels. Conclusion The non-selective cation channels of endothelial cell line ECV304 can be inhibited by tumor necrosis factor TNF-α and A9C.