七氟醚麻醉对局灶性脑缺血再灌注大鼠脑组织水通道蛋白9表达的影响

目的 评价七氟醚麻醉对局灶性脑缺血再灌注大鼠脑组织水通道蛋白9( AQP-9)表达的影响.方法 成年雄性SD大鼠75只,体重230～270 g,采用随机数字表法,将其随机分为3组(n=25):假手术组(S组)、缺血再灌注组(UR组)和七氟醚麻醉组(SE组).S组和I/R组静脉注射芬太尼10μg/kg后静脉输注芬太尼25μg·kg-1·h-1,吸入65％N2O和35％O2；SE组吸入2.0％七氟醚和35％ O2.I/R组和SE组采用线栓法制备大鼠局灶性脑缺血再灌注模型,缺血2h后恢复灌注.分别于再灌注6h、1、2、3和5d时测定神经功能缺陷评分和脑组织AQP-9表达,计算脑肿胀率.结果 与S组比较,I/R组和SE组再灌注6h、1、2、3和5d时神经功能缺陷评分升高,再灌注1、2、3d时脑肿胀率升高,再灌注1、2、3和5d时脑组织AQP-9表达上调(P＜0.05)；与I/R组比较,SE组再灌注2和3d时神经功能缺陷评分下降,脑肿胀率降低,再灌注2、3和5d时脑组织AQP-9表达上调(P＜0.05).结论 七氟醚麻醉减轻大鼠局灶性脑缺血再灌注损伤的机制与上调脑组织AQP-9的表达有关.

Effects of sevoflurane anesthesia on aquaporin-9 expression in brain tissue after focal cerebral ischemiareperfusion in rats

Objective To investigate the effects of sevoflurane anesthesia on aquaporin-9 (AQP-9) expression in brain tissue after focal cerebral ischemia-reperfusion (I/R) in rats.Methods Seventy-five male SD rats weighing 230-270 g were randomly divided into 3 groups ( n =25 each):group sham operation (group S) ; group I/R and group sevoflurane anesthesia (group SE).All the animals were tracheally intubated under 2.0％ sevoflurane and mechanically ventilated.Anesthesia was maintained with fentanyl infusion at 25 μg· kg-1 · h-1 after a bolus of fentanyl 10 μg/kg and inhalation of 65％ N2O in O2 in groups S and I/R and with inhalation of 2％ sevoflurane in 35％ O2 in group SE.Focal cerebral ischemin was induced by occlusion of middle cerebral artery for 2 h using a nylon thread with rounded tip which was inserted into the right internal carotid artery and advanced cranially until resistance was met.The neurologic function was assessed and scored (0=no deficit,4 =unable to move,unconscious) and brain edema rate (volume of ischemic hemisphere-volume of contralateral hemisphere ÷volume of contralateral hemisphere × 100％ ) and expression of AQP-9 were determined at 6 h,1,2,3 and 5 d of reperfusion.Results Focal cerebral I/R significantly increased neurologic deficit scores,brain edema rate and AQP-9 expression in brain tissue in group I/R as compared with group S.Sevoflurane anesthesia significantly attenuated the I/R-induced increase in neurologic deficit scores and brain edema rate and further increased I/R-induced increase in AQP-9 expression in brain tissue.Conclusion Sevoflurane anesthesia can reduce focal cerebral I/R injury by up-regulating the expression of AQP-9 in brain tissue.