Zhang Wei-Dong, Zhang Hao, Wang Hai, Zhang Na, DU Chun-Yan, Yu Jun, Feng Ze-Guo
Anesthesia and Operation Center, General Hospital of PLA, Beijing, 100853, China. E-mail:
Nan Fang Yi Ke Da Xue Xue Bao. 2016 Feb 20;37(2):150-156. doi: 10.3969/j.issn.1673-4254.2017.02.02.
To investigate the protective effects of dexmedetomidine (Dex) against glutamate-induced cytotoxicity in PC12 cells and its mechanism.
PC12 cells were treated with varying concentrations of dexmedetomidine 1 h before exposure to a high concentration of glutamate. The cell viability was measured by MTT assay, and LDH release, MDA content and SOD activity were measured. The level of ROS was tested by DCFH-DA staining and flow cytometry. The level of intracellular Ca was detected by Fluo-8 staining and flow cytometry, and the mitochondrial membrane potential (MMP) was determined with JC-1 staining and flow cytometry.
Within the concentration range of 0.01 to 100 µmol/L, Dex dose-dependently protected PC12 cells against glutamate-induced cytotoxicity. Treatment with 100 µmol/L Dex significantly increased the cell viability to (86.6∓2.2)% of that of the control cells (P<0.01) and decreased LDH release to 1.4∓0.1 folds of the control level (P<0.01). In PC12 cells exposed to glutamate, Dex pretreatment significantly reduced MDA content (P<0.01), enhanced SOD activity (P<0.01), inhibited ROS overproduction (P<0.01), reduced intracellular Ca level (P<0.01) and maintained a stable MMP (P<0.01).
Dexmedetomidine can protect PC12 cells against glutamate-induced injury possibly in relation with its anti-oxidative activity, inhibitory effect on intracellular calcium overload and protective effect of the mitochondria.
探讨右美托咪定（Dex）对谷氨酸诱导的PC12细胞毒性的保护作用及其机制。
在暴露于高浓度谷氨酸前1小时，用不同浓度的右美托咪定处理PC12细胞。通过MTT法测定细胞活力，并测定乳酸脱氢酶（LDH）释放、丙二醛（MDA）含量和超氧化物歧化酶（SOD）活性。通过DCFH-DA染色和流式细胞术检测活性氧（ROS）水平。通过Fluo-8染色和流式细胞术检测细胞内钙水平，并用JC-1染色和流式细胞术测定线粒体膜电位（MMP）。
在0.01至100μmol/L的浓度范围内，Dex呈剂量依赖性地保护PC12细胞免受谷氨酸诱导的细胞毒性。用100μmol/L Dex处理可使细胞活力显著增加至对照细胞的（86.6±2.2）%（P<0.01），并使LDH释放降至对照水平的1.4±0.1倍（P<0.01）。在暴露于谷氨酸的PC12细胞中，Dex预处理可显著降低MDA含量（P<0.01），增强SOD活性（P<0.01），抑制ROS过度产生（P<0.01），降低细胞内钙水平（P<0.01）并维持稳定的MMP（P<0.01）。
右美托咪定可保护PC12细胞免受谷氨酸诱导的损伤，这可能与其抗氧化活性、对细胞内钙超载的抑制作用以及对线粒体的保护作用有关。
