右美托咪啶预先给药对大鼠局灶性脑缺血再灌注损伤的影响  

Effect of dexmedetomidine pretreatrnent on focal cerebral ischemia-reperfusion injury in rats

作　　者：李波[1] 吕国义[1] 邓迺封[1] 

机构地区：[1]天津医科大学第二医院麻醉科,300211

出　　处：《中华麻醉学杂志》2011年第11期1381-1383,共3页Chinese Journal of Anesthesiology

摘　　要：目的评价右美托咪啶预先给药对大鼠局灶性脑缺血再灌注损伤的影响。方法健康雄性SD大鼠100只，体重290～310g，采用随机数字表法，将其随机分为5组（n=20）：假手术组（SH组）、缺血再灌注组（I／R组）和不同剂量右美托咪啶预先给药组（L组、M组和H组）。I／R组、L组、M组和H组采用线栓法建立大鼠局灶性脑缺血再灌注损伤模型，缺血60min后行再灌注。L组、M组和H组于缺血前15min分别腹腔注射右美托咪啶100、200和400μg/kg，I／R组腹腔注射等容量生理盐水。再灌注24h时，随机取10只大鼠，测定神经功能缺陷评分和脑梗死体积，观察脑组织病理学改变；随机取10只大鼠，测定缺血侧脑组织热休克蛋白70（HSP70）表达、Na^＋-K^＋-ATP酶活性和血浆SOD活性、皮质醇浓度。结果与SH组比较，I／R组、L组、M组和H组神经功能缺陷评分和皮质醇浓度升高，SOD和Na^＋-K^＋-ATP酶的活性降低，HSP70表达上调（P〈0．05）；与I／R组比较，L组、M组和H组神经功能缺陷评分、脑梗死体积和皮质醇浓度降低，HSP70表达上调，SOD和Na^＋-K^＋-ATP酶的活性升高，且呈剂量依赖性（P〈0．05），病理学损伤程度呈剂量依赖性减轻。结论右美托咪啶预先给药可减轻大鼠局灶性脑缺血再灌注损伤，且呈剂量依赖性，其机制可能与改善脑细胞能量代谢、减轻脂质过氧化反应和应激反应有关。Objective To investigate the effect of dexmedetomidine pretreatment on focal cerebral isch- emia-reperfusion（I/R） injury in rats. Methods One hundred male SD rats weighing 290-310 g were randomly divided into 5 groups（ n = 20 each） ：sham operation group（group SH） ; focal cerebral I/R group; focal cerebral I/R ＋ dexmedetomidine 100 μg/kg（group L）; focal cerebral I/R ＋ dexmedetomidine 200 μg/kg （group M） and focal cerebral I/R ＋ dexmedetomidine 400 μg/kg（group H）. Focal cerebral I/R was produced by occlusion of middle cerebral artery for 60 rain followed by 24 h of reperfusion. Dexmedetomidine 100, 200 and 400 μg/kg were injected intraperitoneally t5 rain before ischemia in groups L, M and H respectively. While equal volume of normal saline was injected intraperitoneally in group SH. Neurologic function was assessed and scored at 24- h of reperfusion. Then the animals were sacrificed and brains were removed for determination of cerebral infarct volume and microscopic examination. The expression of heat shock protein 70（HSPT0） and activity of Na^＋-K^＋ -ATPase in isehemic cortex and activity of SOD and concentration of cortisol in plasma were determinationed at 24 h of reperfusion. Resuits Compared with group SH, neurologic deficit scores and plasma concentration of cortisol were significantly increased, activities of SOD and Na^＋ -K^＋ -ATPase decreased and expression of HSPT0 was up-regulated in groups I/R, L, M and H（P 〈 0.05）. Compared with group I/R, nearologic deficit scores and plasma concentration of cortisol were significantly decreased, activities of SOD and Na^＋ -K^＋ -ATPase increased and expression of HSP70 was up-regulated in a dose-dependent manner （P 〈 0.05）, and the pathological change was reduced in a dose-dependent manner in groups L, M and H. Conclusion Dexmedetomidine pretreatment can attenuate focal cerebral I/ R injury in a dose-dependent manner through improvement of brain cell energy metabolism and reduction of lipid peroxidation a

关 键 词：右美托咪啶 脑 再灌注损伤 

分 类 号：R614[医药卫生—麻醉学]