依托咪酯对过氧化氢损伤PC12细胞株的保护作用

Neuroprotective Effects of Etomidate on H_2O_2 Induced Injury in Neuronal PC12 Cells

目的研究依托咪酯对过氧化氢损伤神经元样嗜铬细胞瘤细胞株(PC12)的游离Ca2+作用。方法PC12细胞株接种于6孔细胞培养板,随机分为损伤组(I组)和依托咪酯3μmol/L组(E1组)、6μmol/L组(E2组)和15μmol/L组(E3组)。分别加入含标记Ca2+的荧光染色剂Fluo310μmol/L的培养基,37℃孵育30min,置入激光共聚焦显微镜扫描仪连续扫描,并于开始连续扫描2次后加入100μmol/L H2O2,动态观察各组细胞内游离Ca2+浓度([Ca2+]i)的变化。结果I组加入H2O2后,90%的细胞立即有反应,细胞[Ca2+]i荧光密度即开始增高(P<0.05),并在10s后呈现明显变化(P<0.01),80s达到峰值并呈持续稳定状态。依托咪酯各浓度组在加入H2O2后约10%细胞有反应,但其细胞[Ca2+]i荧光密度呈现平稳波动。E1和E2组在50s后,细胞[Ca2+]i荧光密度开始下降(P<0.05),但不呈继续降低趋势。结论依托咪酯通过抑制H2O2损伤引起的神经细胞内[Ca2+]i持续增高,而发挥其神经保护作用。

Objective To investigate the effect of etomidate to intracellular free calcium （ [ Ca^2＋] i ） concentration changes in response to H2O2-induced injury on the neuronal PC12 cells. Methods PC12 pheochromocytoma cell lines were plated in 20 mm diameter cell culture dishes and randomly divided into injury group （Ⅰ group） and three etomidate groups （E1, E2 and E3 ） with different concentrations （3μmol/L, 6μmol/L and 15μmol/L）. The [ Ca^2 ＋ ] i changes were continuously measured by the confocal laser scanning microscope after incubation at 37℃for 30 min in 10μmol/L Fluo 3 enriched media and induction by 100μmol/L H2O2in each group from the third scanning. Results The fluorescence of 90% PC12 cells increased immediately after H2O2-induced injury（P 〈0.05） and had significant changes at 10 s reaching the top at 80 s in I group（P 〈0.01）. Fluorescence of 10% PC12 cells of each E group fluctuated and decreased slightly in E2 group and E2group （P 〈 0.05） after 50 s. Conclusion Etomidat can protect neuronal PC12 cells by inhibiting[ Ca^2＋]i increase on H2O2-induced injury.