Wang Zhi-Ping, Zhang Zhao-Hang, Zeng Yin-Ming, Jiang Shan, Wang Shu-Qu, Wang Sheng
Department of Anesthesiology, Affiliated Hospital of Xuzhou Medical College, Jiangsu Province Institute of Anesthesiology, Xuzhou 221002, China.
Sheng Li Xue Bao. 2006 Jun 25;58(3):201-6.
To investigate the neuroprotective effects of sevoflurane preconditioning on oxygen-glucose deprivation (OGD) injury and the role of mitochondrial KATP channels in rat, we established OGD injury model in rat hippocampal slices. The brain was rapidly removed, and the dissected hippocampus was sliced in cold artificial cerebrospinal fluid (ACSF) transversely to its longitudinal axis (400 mum thick) with a Rotorslicer DTY-7700. Slices were placed on a nylon mesh in a recording chamber at 34 degrees C and humidified gas mixture (95% O2/5% CO2) was applied to the chamber at a flow rate of 200 ml/min. After 2 h of incubation, slices were randomly exposed to 2%, 4%, 6% sevoflurane or 6% sevoflurane combined with mitochondrial K(ATP) channel blocker (5-hydroxydecanoic acid, 5-HD) under normal condition (95% O2/5% CO2) for 30 min. Fifteen minutes later, slices were exposed to 14-minute OGD followed by 1-hour reoxygenation, and the changes of orthodromic population spike (OPS) at the end of reoxygenation were measured. The changes of ultrastructure of CA1 area in the group of 14-minute OGD followed by 1-hour reoxygenation were detected with electron microscope. The results showed that sevoflurane preconditioning delayed the abolishing time of OPS (P<0.01) and significantly increased the recovery rate and the recovery amplitude of OPS compared with the OGD group. The recovery rate of OPS was 71.4% both in 4% and 6% sevoflurane preconditioning groups (P<0.05 vs OGD group), accordingly the recovery amplitude of OPS was (61.0 +/- 42.3)% and (78.7 +/- 21.1)% (P<0.01), respectively. The protective effect of 6% sevoflurane was blocked by 5-HD. Ultrastructural observation in the hippocampal CA1 region of the OGD group showed severe edema of the pyramidal cells, crimpled or ruptured nucleus membranes, aggregation of chromatin, and swelling of mitochondria, whereas these changes were less prominent in 4% and 6% sevoflurane groups. These results suggest that sevoflurane preconditioning is capable to protect neurons from OGD injury in vitro and that the protective effect is related to the activation of mitochondrial K(ATP) channels.
为研究七氟醚预处理对大鼠氧糖剥夺（OGD）损伤的神经保护作用及线粒体ATP敏感性钾通道（mitochondrial KATP channels）的作用，我们建立了大鼠海马脑片OGD损伤模型。迅速取出大鼠脑，用DTY - 7700型切片机在冰冷的人工脑脊液（ACSF）中沿海马纵轴横向切成薄片（400μm厚）。脑片置于记录槽内的尼龙网上，于34℃，以200ml/min的流速向槽内通入含95% O₂/5% CO₂的湿润混合气体。孵育2h后，在正常条件（95% O₂/5% CO₂）下，将脑片随机暴露于2%、4%、6%七氟醚或6%七氟醚联合线粒体K(ATP)通道阻断剂（5 - 羟基癸酸，5 - HD）中30min。15min后，使脑片经历14min的OGD，随后复氧1h，测量复氧结束时顺向群体峰电位（OPS）的变化。用电子显微镜检测经历14min OGD后复氧1h组海马CA1区超微结构的变化。结果显示，与OGD组相比，七氟醚预处理延迟了OPS消失时间（P<0.01），并显著提高了OPS的恢复率和恢复幅度。4%和6%七氟醚预处理组OPS的恢复率均为71.4%（与OGD组相比，P<0.05），相应地，OPS的恢复幅度分别为(61.0±42.3)%和(78.7±21.1)%（P<0.01）。6%七氟醚的保护作用被5 - HD阻断。OGD组海马CA1区的超微结构观察显示锥体细胞严重水肿，核膜皱缩或破裂，染色质聚集，线粒体肿胀，而在4%和6%七氟醚组中这些变化不那么明显。这些结果表明，七氟醚预处理能够在体外保护神经元免受OGD损伤，且其保护作用与线粒体K(ATP)通道的激活有关。
