肿瘤坏死因子α作用后脐静脉内皮细胞质内钙离子的变化

The variation of intracytosolic free [Ca^(2+) ]_i in HUVECs induced by TNF-α

目的 :观察不同浓度肿瘤坏死因子α(TNF α)对培养人脐静脉内皮细胞质内钙离子变化的影响。 方法 :用Fluo 3作为钙指示剂 ,用激光共聚焦显微镜观察测定不同浓度TNF α作用后脐静脉内皮细胞质内钙离子 [Ca2 + ]i的变化。 结果 :① 10 5U/mlTNF α刺激后 ,脐静脉内皮细胞内 [Ca2 + ]i水平迅速升高。随着TNF α刺激浓度的下降 ,内皮细胞内 [Ca2 + ]i升高波峰亦逐渐下降 ,10 2 U/mlTNF α作用后内皮细胞内 [Ca2 + ]i水平无显著变化。②用D Hanks液平衡后 ,10 5U/mlTNF α刺激后脐静脉内皮细胞内 [Ca2 + ]i的水平迅速下降 ,随着TNF α刺激浓度的下降 ,内皮细胞内 [Ca2 + ]i下降波峰亦逐渐减缓 ;与此同时 ,细胞外液中Ca2 + 水平逐渐升高。③用EGTA预处理后 ,不同浓度TNF α作用后脐静脉内皮细胞质内外Ca2 + 水平无显著变化。 结论 :TNF α可使内皮细胞膜钙离子通透性增高 。

Objectives: To study the influences of TNF α at different doses on the concentration changes of intracytosolic free calcium ion(\[Ca 2+ \] i ) in human umbilical vein endothelial cells(HUVECs). Methods: Fluo 3 labeling method and confocal laser scanning microscopy were used to observe the variation of \[Ca 2+ \] i . Results:①When the culture medium were balanced by Hanks Buffer, \[Ca 2+ \] i in HUVECs increased quickly when cells were stimulated by TNF α at 10 5 U/ml. The increasing range of the concentration of \[Ca 2+ \] i decreased when the stimulating dose of TNF α decreased. There was no increase of the concentration of \[Ca 2+ \] i when the cells were stimulated by TNF α at 10 2 U/ml.②When the culture medium were balanced by D Hanks Buffer, intracytosolic free \[Ca 2+ \] i in HUVECs decreased remarkably when cells were stimulated by TNF α at 10 5 U/ml. When the stimulating dose of TNF α decreased, the decreasing range of the concentration of \[Ca 2+ \] i also decreased . At the same time, extracytosolic free calcium ion increased gradually. ③When HUVECs were pretreated with EGTA, there were no variation of intracytosolic free Ca 2+ in HUVECs when cells were stimulated by TNF α at different doses. Conclusions: TNF α could improve the membrane permeability of calcium ion in HUVECs. This was related to the apoptosis or cytotoxicity of HUVECs.