七氟醚预处理对氧糖缺失大鼠海马脑片的影响：酪氨酸激酶和缺血时间的作用  

作　　者：姚凤珍(译) 崔苏(扬校) 

出　　处：《麻醉与镇痛》2012年第6期23-31,共9页Anesthesia & Analgesia

摘　　要：背景实验模型中观察到的麻醉药物的神经保护作用在临床环境中仍未被证实。现有的实验显示，非受体酪氨酸激酶黏着斑激酶（focaladhesionkinase，FAK）参与了麻醉药物的神经保护作用。本实验中，我们研究在应用七氟醚对脑组织进行预处理时，FAK以及脑缺血时间是否发挥了作用。方法大鼠急性海马脑片进行氧糖缺失处理（oxygenandglucosedeprivation，OGD），时间逐步增加（10分钟、20分钟、30分钟、45分钟、50分钟、60分钟），继之行再灌注1小时。OGD启动前3小时进行七氟醚预处理（浓度为10-4M，1小时）。免疫印迹法测定FAK以及caspase3（凋亡级联反应启动的标志物）的表达水平。碘化丙啶（propidiumiodide，PI）荧光测定细胞死亡。结果H免疫荧光与caspase3表达随着缺血时间的延长而显著增加，直至缺血时间超过30分钟后达到封顶效应。七氟醚预处理（10-4M）使FAK表达增加，并显著减轻了缺血10分钟、20分钟和30分钟的PI免疫荧光以及caspase3表达水平的增加。相反，缺血时间超过30分钟后不再观察到这种保护效应。七氟醚预处理前60分钟以及整个预处理过程中使用4-氨基-5-（4-氯苯基）-7-（t-丁基）吡唑[3，4-d]嘧啶（PP2，10-5M，Src酪氨酸激酶抑制剂）显著削弱了七氟醚在caspase3以及PI免疫荧光方面的神经保护作用。结论在氧糖缺失的急性大鼠海马脑片中，临床相应浓度的七氟醚的预处理效应与FAK密切相关，并且只在缺血时间短于30分钟的情况下可以观察到。BACKGROUND： The neuroprotective efficacy of anesthetics observed in experimental models remains unproven in the clinical setting. The nonreceptor tyrosine kinase focal adhesion kinase （FAK） has been suggested to be involved in the neuroprotective effect of anesthetics observed experimentally. In the present work, we investigated whether FAK and the duration of ischemia play a role in the preconditioning effect of sevoflurane on brain tissue. METHODS： Rat acute hippocampal slices were subjected to oxygen and glucose deprivation （OGD） challenge during increasing periods of time （10, 20, 30, 45,50, and 60 min） followed by I h reperfusion. A preconditioning sevoflurane concentration （10-4 M, 1 h） was applied 3 h before initiation of OGD. Protein expression of FM（ and deaved caspase 3 （a marker of activation of the apoptotic cascade） was measured by immunoblotting. Cell death was assessed by propidium iodide （PI） fluorescence. RESULTS： Both PI fluorescence and expression of cleaved caspase 3 significantly increased with duration of ischemia until reaching a ceiling effect for durations of ischemia longer than 30 min. Sevoflurane （10 -4 M） increased FAK expression and markedly reduced the increase in PI fluorescence and cleaved caspase 3 expression for periods of ischemia of 10, 20, and 30 min. In contrast, the protective effect was no longer observed for periods of ischemia longer than 30 min. 4-amino-5- （4-chlorophenyl） -7- （t- butyl） pyrazolo [3,4-dl pyrimidine （PP2, 10-5 M, an inhibitor of src tyrosine kinases） application 60 min before and throughout that of sevoflurane significantly reduced the neuroprotective effect of sevoflurane on both caspase 3 expression and PI fluorescence. CONCLUSIONS： In the OGD rat acute hippocampal slice, the preconditioning effect of a clinically relevant concentration of sevoflurane was very likely to involve FAK and was observed only for periods of ischemia ≤30 min.

关 键 词：受体酪氨酸激酶 预处理效应 缺血时间 海马脑片 氧糖缺失 七氟醚 CASPASE3 大鼠 

分 类 号：R979.1[医药卫生—药品]