【摘要】 利用离体海马脑片缺氧无糖（oxygen-glucose deprivation,OGD）损伤模型,探讨七氟醚预处理对神经细胞的保护作用及陔作用与线粒体内膜ATP敏感钾通道(mitochondrial ATP-sensitive potassium channels,mitoK_ATPchannels)的关系,随机将脑片用2%、4%、6%七氟醚,以及6%七氟醚复合mitoK_ATP通道阻滞剂5-羟基奎酸盐（5-hydroxydecanoic acid,5-HD）预处理30min,观察OGD损伤14min复氧1h期间顺向群峰电位（orthodromic population spike,OPS）的变化,并应用透射电镜观察细胞超微结构的改变。结果表明,与单纯OGD组相比,七氟醚预处理可使海马脑片OPS消失时间明显延长（P＜0．01）,使OPS明显恢复,其中4%、6%七氟醚组的恢复率均为71．4%（P＜0．05 vs OGD）,相应恢复程度为（61．0±42．3）%和（78．7±21．1）%（P＜0．01）,而且6%七氟醚的保护作用可被5-HD取消。OGD组的海马CA1区锥体细胞明显水肿,核膜皱缩、破裂,染色质聚集,线粒体肿胀畸形,嵴断裂或消失,而4%和6%七氟醚组仅见海马CA1区锥体细胞轻度水肿,核膜皱缩不明显,染色质均匀,线粒体轻度肿胀。结果提示,七氟醚预处理对大鼠海马脑片OGD损伤有一定的保护作用,且七氟醚对神经细胞的保护作用与激活mitoK_ATP通道有关。更多还原

【Abstract】 To investigate the neuroprotective effects of sevoflurane preconditioning on oxygen-glucose deprivation （OGD） injury and the role of mitochondrial K_ATP 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 （400μm thick） with a Rotorslicer DTY-7700.Slices were placed on a nylon mesh in a recording chamber at 34℃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.更多还原