中文摘要：

目的探讨七氟醚对小鼠脑干细胞外信号调节激酶（ERK1/ERK2）磷酸化的影响,筛查脑干中与麻醉效应有关的核团。方法BALB/c小鼠60只,8周龄,体重20～25g,随机分为5组（n= 12）,对照组（Con组）无麻醉处理;Sevo-1组七氟醚麻醉5min;Sevo-2组七氟醚麻醉1h;E-1组七氟醚麻醉1h,洗脱2min;E-2组七氟醚麻醉1h,洗脱1h。各组麻醉结束后处死小鼠,取6只小鼠,制备脑干组织切片,采用Western blot法测定脑干ERK1/ERK2和磷酸化ERK1/ERK2（p-ERK1/ERK2）的表达;取6只小鼠,采用免疫组化法测定脑干不同核团p-ERK1/ERK2的表达。结果各组脑干ERK1/ERK2表达差异无统计学意义（P〉0.05）。与Con组相比,其余4组脑干p-ERK1/ERK2表达水平升高（P〈0.01）,而4组间差异无统计学意义（P〉0.05）。光镜下可见孤束核（Sol）、延髓腹外侧网状核（LRt）、臂旁外侧核背侧亚核（LPBD）、中脑室周灰质腹外侧核（vLPAG）和动眼神经副核（EW）中有p-ERK1/ERK2表达。与Con组比较,Sevo-1组、Sevo-2组和E-1组LRt、Sol、EW、LPBD的p-ERK1/ERK2表达升高,vLPAG的p- ERK1/ERK2表达降低,E-2组LPBD的p-ERK1/ERK2表达升高（P〈0.05或0.01）。与Sevo-2组比较,Sevo-1组和E-1组LPBD及E-2组LRt、Sol、EW、LPBD的p-ERK1/ERK2表达降低,E-2组vLPAG的p- ERK1/ERK2表达升高（P〈0.05或0.01）。结论七氟醚麻醉时脑干核团p-ERK1/ERK2的改变可能参与了其全麻效应的中枢机制。

英文摘要：

Objective To investigate the effect of sevoflurane on p44/p42 extracellular signal-regulated kinase （ERK1/ERK2） phosphorylation in brainstem and to sort out the nuclei in brainstem which may be associated with anesthetic effect.Methods Sixty 8-week old BALB/c mice weighing 20-25 g were randomly divided into 5 groups （n=12 each）：one control group （groupⅠ） and 4 sevoflurane groups in which anesthesia was induced with 4% sevoflurane until loss of righting reflex and then maintained with 2.5% sevoflurane （groupⅡ-Ⅴ）.GroupⅡandⅢinhaled sevoflurane for 5 min （Sevo-1） and 1 h （Sevo-2） respectively while groupⅣandⅤinhaled sevoflurane for 1 h followed by 2 min （E-1） and 1 h （E-2） emergence.The animals were then killed by cervical dislocation and the brainstems were immediately removed for determination of phosphorylated ERK1/ERK2 expression using Western blot and immuno-histochemical staining.Results （1） Western blotting showed that p-ERK1/ERK2 expression in the brainstem was significantly increased in groupⅡ-Ⅴ（Sevo-1,Sevo-2,E-1,E-2） as compared with control group.（2） Immuno-histochemical staining showed that there were significantly more p-ERK1/ERK2 positive neurons in lateral reticular nucleus,solitary tract nucleus,Edinger-Westphal （E-W） nucleus and dorsal part of lateral parabrachial nucleus （LPBD） in Sevo-1,Sevo-2 and E-1 groups than in control group （P〈0.05 or 0.01） while no significant difference in the number of p-ERK1/ERK2 positive neurons was found in the above nuclei except the dorsal part of LPBD between E-2 group and control group.（3）On the contrary the number of p-ERK1/ERK2 positive cells in ventrolateral periaqueductal gray was significantly decreased in Sevo-1,Sevo-2 and E-1 groups as compared with control group （P〈0.05 or 0.01） while no significant difference was found in the number of p-ERK1/ERK2 positive neurons in ventrolateral periaqueductal gray between E-2 and control groups （P〉0.05）.Conclusion The changes in