小鼠脑出血后不同时间点小胶质细胞极化状态的实验研究

目的 观察小鼠脑出血后不同时间点小胶质细胞M1及M2型的转化,为促炎型M1型小胶质细胞向抗 炎修复型M2型小胶质细胞的转化,减轻脑出血后神经功能损伤提供理论依据。 方法 选取健康雄性ICR小鼠48只,随机分为假手术组、脑出血组,每组按术后时间点不同随机 分为1 d、3 d、7 d三个时间点,每个时间点8只。通过立体定位仪用微量注射器向尾状核注射Ⅳ型胶 原酶0.5 U制备脑出血模型,假手术组注射等量生理盐水。各组于术后对应时间点参照改良Garcia 评分量表进行神经功能缺损评分后灌注取脑,采用蛋白免疫印迹检测M1型小胶质细胞标志物肿瘤 坏死因子α（tumor necrosis factor-α,TNF-α）、白细胞介素6（interleukin-6,IL-6）,M2型小胶质细胞 标志物脑源性神经营养因子（brai n-derived neurotrophic factor,BDNF）、胰岛素样生长因子1（insulinlike growth factor 1,IGF-1）的含量;采用免疫荧光染色标记小胶质细胞M1型（Iba1+CD80）、M2型 （Iba1+CD206）,评价出血后血肿周围组织小胶质细胞活化状态。 结果 脑出血组1 d、3 d、7 d各时间点Garci a评分均较假手术组低,TNF-α、IL-6、BDNF及I GF-1的蛋白 表达量均较假手术组增多（均P＜0.01）。脑出血后1 d时M1型高于M2型小胶质细胞数量（38.33±1.53 vs 23.00±3.00,P =0.01）;3 d时M1型同样高于M2型（66.33±3.06 vs 57.33±2.52,P =0.02）;7 d时M1 型低于M2型（33.67±1.15 vs 52.33±0.58,P＜0.01）。 结论 脑出血急性期（1～3 d）以M1型小胶质细胞为主,脑出血亚急性期（7 d）以M2型小胶质细胞 为主。     

局灶脑缺血恢复期半影区小胶质细胞可塑性变化和bFGF表达规律探讨

目的观察Wistar大鼠大脑中动脉永久性闭塞后不同时段,缺血半影区小胶质细胞和神经元形态学变化及bFGF在皮层和海马的表达规律。方法将雄性Wistar大鼠48只,随机分为假手术对照组和永久性局灶性脑缺血组,后者再根据缺血时间不同分5个亚组。假手术组:仅暴露大脑中动脉,2h后断头取脑。永久性局灶性脑缺血组:建立大鼠大脑中动脉闭塞模型,分别于缺血后3d、7d、14d、28d、42d断头取脑,行HE和免疫组化染色。观察梗死灶周围半影区的小胶质细胞和神经元的形态学变化和bFGF在皮层及海马部位的表达规律。结果HE染色可见脑缺血3d时半影区有少量小胶质细胞出现,14d小胶质细胞增多达高峰,42d趋于稳定。脑缺血3d梗死灶周围皮质神经元和胶质细胞开始表达bFGF,7d表达增强,14d达高峰,28d表达开始减弱,42d仍有一定表达,bFGF在海马的表达也有相同规律。结论小胶质细胞的肥大和增生性变化以及bFGF的表达,不仅发生于脑缺血早期,晚期仍显示持续性变化,表明小胶质细胞活动以及bFGF的表达贯穿于脑缺血的整个病理过程。     

局灶脑缺血恢复期半影区小胶质细胞可塑性变化和bFGF表达规律探讨

目的 观察Wistar大鼠大脑中动脉永久性闭塞后不同时段，缺血半影区小胶质细胞和神经元形态学变化及bFGF在皮层和海马的表达规律。方法 将雄性Wistar大鼠48只，随机分为假手术对照组和永久性局灶性脑缺血组，后者再根据缺血时间不同分5个亚组。假手术组：仅暴露大脑中动脉，2h后断头取脑。永久性局灶性脑缺血组：建立大鼠大脑中动脉闭塞模型，分别于缺血后3d、7d、14d、28d、42d断头取脑，行HE和免疫组化染色。观察梗死灶周围半影区的小胶质细胞和神经元的形态学变化和bFGF在皮层及海马部位的表达规律。结果 HE染色可见脑缺血3d时半影区有少量小胶质细胞出现，14d小胶质细胞增多达高峰，42d趋于稳定。脑缺血3d梗死灶周围皮质神经元和胶质细胞开始表达bFGF，7d表达增强，14d达高峰，28d表达开始减弱，42d仍有一定表达，bFGF在海马的表达也有相同规律。结论 小胶质细胞的肥大和增生性变化以及bFGF的表达，不仅发生于脑缺血早期，晚期仍显示持续性变化，表明小胶质细胞活动以及bFGF的表达贯穿于脑缺血的整个病理过程。     

小鼠脑出血后不同时间点小胶质细胞极化状态的实验研究

目的 观察小鼠脑出血后不同时间点小胶质细胞M1及M2型的转化，为促炎型M1型小胶质细胞向抗
炎修复型M2型小胶质细胞的转化，减轻脑出血后神经功能损伤提供理论依据。
方法 选取健康雄性ICR小鼠48只，随机分为假手术组、脑出血组，每组按术后时间点不同随机
分为1 d、3 d、7 d三个时间点，每个时间点8只。通过立体定位仪用微量注射器向尾状核注射Ⅳ型胶
原酶0.5 U制备脑出血模型，假手术组注射等量生理盐水。各组于术后对应时间点参照改良Garcia
评分量表进行神经功能缺损评分后灌注取脑，采用蛋白免疫印迹检测M1型小胶质细胞标志物肿瘤
坏死因子α（tumor necrosis factor-α，TNF-α）、白细胞介素6（interleukin-6，IL-6），M2型小胶质细胞
标志物脑源性神经营养因子（brai n-derived neurotrophic factor，BDNF）、胰岛素样生长因子1（insulinlike
growth factor 1，IGF-1）的含量；采用免疫荧光染色标记小胶质细胞M1型（Iba1+CD80）、M2型
（Iba1+CD206），评价出血后血肿周围组织小胶质细胞活化状态。
结果 脑出血组1 d、3 d、7 d各时间点Garci a评分均较假手术组低，TNF-α、IL-6、BDNF及I GF-1的蛋白
表达量均较假手术组增多（均P＜0.01）。脑出血后1 d时M1型高于M2型小胶质细胞数量（38.33±1.53
vs 23.00±3.00，P =0.01）；3 d时M1型同样高于M2型（66.33±3.06 vs 57.33±2.52，P =0.02）；7 d时M1
型低于M2型（33.67±1.15 vs 52.33±0.58，P＜0.01）。
结论 脑出血急性期（1～3 d）以M1型小胶质细胞为主，脑出血亚急性期（7 d）以M2型小胶质细胞
为主。     

雪莲提取物对脑缺血再灌注损伤小鼠海马区星形胶质细胞胶质纤维酸性蛋白和小胶质细胞离子钙接头蛋白的影响

目的探讨雪莲提取物对缺血再灌注损伤小鼠海马区星形胶质细胞胶质纤维酸性蛋白(GFAP)和小胶质细胞离子钙接头蛋白(Iba1)表达的影响。方法 40只昆明小鼠随机分为假手术组、缺血再灌注组和雪莲提取物低、中、高剂量组。采用线栓法制作大脑中动脉闭塞模型。雪莲提取物低、中、高剂量组小鼠术前7 d分别连续腹腔注射0.2 g/(kg·d)、0.4 g/(kg·d)、0.8 g/(kg·d)雪莲注射液。假手术组不闭塞大脑中动脉,给予等体积中剂量雪莲注射液。缺血再灌注组再灌时腹腔注射等体积生理盐水。再灌注24 h后采用免疫组化染色法检测GFAP和Iba1的表达。结果与假手术组比较,缺血再灌注组及雪莲提取物低、中剂量组GFAP阳性细胞数明显增加,缺血再灌注组及雪莲提取物低、中、高剂量组IBA1阳性细胞数明显增加(均P0.01);与缺血再灌注组比较,雪莲提取物低、中、高剂量组GFAP及IBA1阳性细胞数明显减少(均P0.01);与雪莲提取物低剂量组比较,雪莲提取物高剂量组GFAP阳性细胞数明显减少,雪莲提取物中、高剂量组IBA1阳性细胞数明显减少(P0.05~0.01)。结论雪莲提取物可抑制缺血再灌注损伤小鼠海马区星形胶质细胞GFAP和小胶质细胞Iba1的过度表达,有神经保护作用。     

雷帕霉素对小鼠实验性变态反应性脑脊髓炎大脑小胶质细胞活化的影响

目的探讨雷帕霉素对小鼠实验性变态反应性脑脊髓炎(EAE)模型大脑小胶质细胞形态及功能的调节作用。方法小鼠进行EAE造模后分为两组:①生理盐水组(潜伏期腹腔注射生理盐水);②雷帕霉素组(潜伏期腹腔注射雷帕霉素1次/日)。于发病高峰期时处死小鼠取大脑,采用Iba1免疫荧光染色分析大脑皮质小胶质细胞数量及形态;real-time PCR法检测各组小鼠大脑皮质的肿瘤坏死因子α表达量。结果雷帕霉素治疗组与生理盐水组比较,小胶质细胞数明显下降(P 0. 01),形态向M2表型转换。雷帕霉素治疗组与生理盐水组比较,M1表型标记物诱导型一氧化氮合酶及分泌的肿瘤坏死因子α表达量显著下降(P 0. 01)。结论雷帕霉素能抑制小鼠EAE模型大脑小胶质细胞活化,且抑制M1表型小胶质细胞的促炎功能。     

血管性认知障碍小鼠脑内少突胶质细胞再生分化障碍特点研究

目的 观察血管性认知障碍小鼠模型中,缺血性炎性损伤对室管膜下区及海马齿状回少突胶质细胞 再生分化的影响,为血管性认知障碍的缺血性炎症机制提出新的损伤途径。 方法 成年雄性CD1小鼠随机分为模型组和假手术组,每组24只,模型组采用双侧颈动脉反复缺 血再灌注法制备血管性认知障碍小鼠模型。造模后4～6 d连续腹腔注射5 -溴脱氧尿嘧啶核苷 （bromodeoxyuridine,BrdU）（150 mg/kg）标记新生细胞,分别于术后14 d和28 d每组随机取一半小鼠脑 组织进行脑切片免疫组化、免疫荧光双标共聚焦检测,标记脑组织室管膜下区和海马区的少突胶质 细胞、星形胶质细胞及神经元,观察新生少突胶质细胞增殖及分化情况,并观察星形胶质细胞的增 生活化情况。 结果 造模后14 d和28 d室管膜下区新生细胞（BrdU阳性细胞）在模型组较假手术组明显增加（P均 ＜0.001),造模28 d模型组新生神经元（BrdU/NeuN阳性细胞）较假手术组显著增加（P＜0.001)。与假 手术组相比较,术后28 d模型组海马齿状回少突胶质细胞祖细胞显著增多（P＜0.001）;少突胶质细 胞前体细胞显著减少（P =0.006）。造模后28 d模型组海马齿状回新生星形胶质细胞（BrdU/GFAP阳性 细胞）较假手术组显著增加（P =0.015）。 结论 血管性认知障碍小鼠内源性新生细胞增殖区室管膜下区与海马齿状回区均存在新生细胞反 应性增生的情况。新生细胞区分化的主要细胞为星形胶质细胞,而少突胶质细胞分化障碍,可能是血 管性认知障碍患者影像学常见皮层下白质病变的重要原因。     

喹硫平对小鼠脑缺血后胶质增生及IL-1β表达作用的实验研究

目的研究喹硫平对小鼠脑缺血后胶质增生及IL-1β表达的作用。方法实验分为4组:喹硫平加缺血组、药物对照组、缺血组、药物保护组;采用免疫组化法及激光共聚焦显微镜方法检测喹硫平对小鼠脑缺血后胶质增生及IL-1β表达的作用。结果脑缺血再灌后2h小胶质细胞激活,脑缺血再灌后2d和4d小胶质细胞和星形胶质细胞激活;脑缺血再灌后8d、2w和4w喹硫平减少GFAP表达水平。缺血组与假手术组相比较GFAP-IL-1β共表达阳性细胞数量明显增加(P0.01);药物保护组与缺血组比较GFAP-IL-1β共表达细胞数量明显减少(P0.01)。结论喹硫平能够减轻小鼠脑缺血后胶质增生同时降低IL-1β表达水平。     

一种氯化铁诱导血栓生成的小鼠大脑中动脉远端缺血模型

目的 建立稳定的小鼠大脑中动脉远端氯化铁血栓模型,评价其造成的脑损伤及神经功能损伤程 度。 方法 C57BL6/J雄性小鼠随机分为脑缺血组和假手术组。脑缺血组用10%氯化铁（ferric chloride, FeCl3）溶液诱导右侧大脑中动脉远端形成血栓。在术前、术后10 mi n、术后1 d和7 d观测术侧脑血流 和手术动脉血流量的变化。术后1 d观察脑组织梗死率。术后1 d、3 d、5 d、7 d用3种神经学评分[改良 加西亚评分（modified Garcia score,mGS）、改良神经损伤严重程度评分（modified neurological severity scores,mNSS）和15分神经学评估表（15-point neurological evaluation scale,NES）]和胶黏纸测试评价小 鼠神经功能。术后7 d免疫荧光染色标记神经细胞核观察脑组织损伤,标记CD16/32、CD206和Iba1观 察胶质细胞表达。 结果 与假手术组相比,脑缺血组术后10 mi n、1 d、7 d脑表面血流和手术动脉血流下降,术后1 d脑 皮层梗死明显,术后7 d仍有明显脑组织损伤;脑缺血组术后1 d、3 d、5 d和7 d时3种神经学评分及胶 黏纸测试均提示小鼠神经功能不同程度损伤。术后7 d脑缺血组梗死周围皮层M1和M2型胶质细胞表 达增加。 结论 FeCl3溶液可诱导形成稳定的小鼠脑缺血模型,该模型可造成手术侧大脑中动脉远端及脑表 面血流量降低,皮层脑梗死,小鼠神经功能受损,梗死周围胶质细胞表达上调。本研究建立了稳定 氯化铁诱导血栓形成的小鼠脑缺血模型,为脑血栓形成和抗栓药物治疗提供了一种可靠的研究工 具。     

盐酸小檗碱对颅脑创伤模型小鼠双侧丘脑继发性损伤的神经保护作用

目的探讨盐酸小檗碱对颅脑创伤(TBI)模型小鼠双侧丘脑继发性损伤(炎症反应、氧化损伤和神经元缺失)的神经保护作用。方法采用自由落体撞击法制备颅脑创伤模型,盐酸小檗碱组小鼠予以盐酸小檗碱50 mg/(kg·d)灌胃21 d,TBI组予等量生理盐水灌胃21 d,对照组不予自由落体撞击。免疫组织化学染色计数双侧丘脑诱导型一氧化氮合酶(i NOS)、环氧合酶-2(COX-2)、8-羟基脱氧鸟苷(8-OHd G)和神经元核抗原(Neu N)阳性神经元或胶质细胞数目,免疫荧光染色计数双侧丘脑胶质纤维酸性蛋白(GFAP)阳性星形胶质细胞和离子钙结合蛋白1(Iba1)阳性小胶质细胞数目。结果 3组小鼠颅脑创伤同侧丘脑i NOS(P=0.015)、COX-2(P=0.022)、8-OHd G(P=0.000)和Neu N(P=0.000)阳性神经元或胶质细胞数目以及GFAP阳性星形胶质细胞数目(P=0.024)和Iba1阳性小胶质细胞数目(P=0.000)差异均有统计学意义,其中,TBI组i NOS(P=0.005)、COX-2(P=0.011)和8-OHd G(P=0.000)阳性神经元或胶质细胞数目以及GFAP阳性星形胶质细胞数目(P=0.011)和Iba1阳性小胶质细胞数目(P=0.000)均高于对照组,而Neu N阳性神经元数目低于对照组(P=0.000);盐酸小檗碱组i NOS(P=0.031)、COX-2(P=0.024)和8-OHd G(P=0.008)阳性神经元或胶质细胞数目以及GFAP阳性星形胶质细胞数目(P=0.031)和Iba1阳性小胶质细胞数目(P=0.012)均低于TBI组,仅8-OHd G阳性神经元数目(P=0.014)和Iba1阳性小胶质细胞数目(P=0.024)仍高于对照组,而Neu N阳性神经元数目高于TBI组(P=0.016)、仍低于对照组(P=0.027)。3组小鼠颅脑创伤对侧丘脑仅COX-2(P=0.029)和8-OHd G(P=0.000)阳性神经元或胶质细胞数目差异有统计学意义,其中,TBI组COX-2(P=0.011)和8-OHd G(P=0.000)阳性神经元或胶质细胞数目高于对照组,盐酸小檗碱组COX-2(P=0.047)和8-OHd G(P=0.010)阳性神经元或胶质细胞数目低于TBI组,仅8-OHd G阳性神经元数目仍高于对照组(P=0.004)。结论颅脑创伤可以引起双侧丘脑继发性损伤,尤以同侧丘脑显著,对侧丘脑仅出现炎症反应和氧化损伤;盐酸小檗碱通过抑制颅脑创伤后双侧丘脑炎症反应和氧化损伤而发挥神经保护作用。     

High-dose methylprednisolone treatment in experimental focal cerebral ischemia

Previous studies using steroids for experimental focal stroke have demonstrated conflicting results, possibly related to dose used or ischemic models employed. In this study we examined high-dose methylprednisolone treatment following permanent and temporary focal cerebral ischemia in the rat. Focal stroke was induced in spontaneously hypertensive rats by permanent right common carotid and either permanent or 3 h of temporary middle cerebral artery (MCA) occlusion. Methylprednisolone (105 mg/kg) was administered intra-arterially. Infarct volume was measured at 24 h after permanent and temporary MCA occlusion. Cerebral edema was determined by measuring right and left hemispheric volumes and water content 24 h after permanent MCA occlusion in one experiment. Methylprednisolone, whether administered in divided doses over 12 h (n = 15 in each group) or a single bolus (n = 9 per group), had no effect on infarct volume after permanent MCA occlusion. Methylprednisolone treatment also had no influence on cerebral edema (n = 9 per group). In two different experiments, methylprednisolone given in divided doses over 12 h (n = 11, n = 25) after temporary MCA occlusion decreased infarct volume (P < 0.05) by 20% compared with saline controls (n = 10, n = 25). High dose methylprednisolone decreased infarct volume following temporary, but not permanent, focal ischemia. The benefit suggests that high dose methylprednisolone may prove useful clinically if reperfusion can be established with thrombolytic agents. Furthermore, the differential treatment effect in the setting of comparable ischemic insults implies that different modifiable biochemical processes may be present during temporary but not permanent focal ischemia, thus providing indirect evidence for reperfusion injury.     

一种氯化铁诱导血栓生成的小鼠大脑中动脉远端缺血模型

目的 建立稳定的小鼠大脑中动脉远端氯化铁血栓模型，评价其造成的脑损伤及神经功能损伤程
度。
方法 C57BL6/J雄性小鼠随机分为脑缺血组和假手术组。脑缺血组用10%氯化铁（ferric chloride，
FeCl3）溶液诱导右侧大脑中动脉远端形成血栓。在术前、术后10 mi n、术后1 d和7 d观测术侧脑血流
和手术动脉血流量的变化。术后1 d观察脑组织梗死率。术后1 d、3 d、5 d、7 d用3种神经学评分[改良
加西亚评分（modified Garcia score，mGS）、改良神经损伤严重程度评分（modified neurological severity
scores，mNSS）和15分神经学评估表（15-point neurological evaluation scale，NES）]和胶黏纸测试评价小
鼠神经功能。术后7 d免疫荧光染色标记神经细胞核观察脑组织损伤，标记CD16/32、CD206和Iba1观
察胶质细胞表达。
结果 与假手术组相比，脑缺血组术后10 mi n、1 d、7 d脑表面血流和手术动脉血流下降，术后1 d脑
皮层梗死明显，术后7 d仍有明显脑组织损伤；脑缺血组术后1 d、3 d、5 d和7 d时3种神经学评分及胶
黏纸测试均提示小鼠神经功能不同程度损伤。术后7 d脑缺血组梗死周围皮层M1和M2型胶质细胞表
达增加。
结论 FeCl3溶液可诱导形成稳定的小鼠脑缺血模型，该模型可造成手术侧大脑中动脉远端及脑表
面血流量降低，皮层脑梗死，小鼠神经功能受损，梗死周围胶质细胞表达上调。本研究建立了稳定
氯化铁诱导血栓形成的小鼠脑缺血模型，为脑血栓形成和抗栓药物治疗提供了一种可靠的研究工
具。     

CD18-mediated neutrophil recruitment contributes to the pathogenesis of reperfused but not nonreperfused stroke

BACKGROUND AND PURPOSE: Neutrophil (PMN) recruitment mediated by increased expression of intercellular adhesion molecule-1 expression (ICAM-1, CD54) in the cerebral microvasculature contributes to the pathogenesis of tissue injury in stroke. However, studies using blocking antibodies against the common beta2-integrin subunit on the PMN, the counterligand for ICAM-1 (CD18), have demonstrated equivocal efficacy. The current study tested the hypothesis that mice deficient in CD18 would be protected in the setting of reperfused but not nonreperfused stroke. METHODS: Two groups of mice were studied, those whose PMNs could express CD18 (CD18 +/+) and those mice hypomorphic for the CD-18 gene (CD18 -/-). PMNs obtained from CD18 -/- or CD18 +/+ mice were fluorescently labeled and tested for binding to murine brain endothelial monolayers. Using a murine model of focal cerebral ischemia in which an occluding suture placed in the middle cerebral artery (MCA) is removed after 45 minutes (transient ischemia, reperfused stroke) or left in place (permanent ischemia, nonreperfused stroke), cerebral infarct volumes (% ipsilateral hemisphere by TTC staining), cerebral blood flow (CBF, % contralateral hemisphere by laser-Doppler flowmetry), and survival (%) were examined 24 hours after the initial ischemic event. Adoptive transfer studies used 111In-labeled PMNs (from either CD18 +/+ or CD18 -/- mice) to examine the relative accumulation of PMNs in the ischemic region. RESULTS: PMNs obtained from CD18 -/- mice exhibit reduced adhesivity (compared with CD18 +/+ PMNs) for both quiescent and cytokine-activated endothelial monolayers. CD18 -/- mice (n=14) subjected to transient focal cerebral ischemia demonstrated a 53% decrease in infarct volumes versus CD18 +/+ mice (n=26, P<0.05), improved penumbral CBF at 24 hours (1.8-fold, P=0.02), and a 3.7-fold decrease in mortality (P=0.02). However, when CD18 -/- mice (n=12) were subjected to permanent focal cerebral ischemia, no differences were noted in infarct volume, mortality, or CBF versus similarly treated CD18 +/+ mice (n=10). There was a greater accumulation of CD18 +/+ PMNs in the ischemic zone of CD18 +/+ animals than CD18 -/- animals subjected to reperfused stroke (82% increase, P=0.02), although there was no difference between groups when subjected to permanent MCA occlusion. CONCLUSIONS: Deficiency for the CD18 gene confers cerebral protection in a murine model of reperfused stroke, but this benefit does not extend to CD18-deficient animals subjected to permanent MCA occlusion. These data suggest that anti-PMN strategies should be targeted to reperfused stroke and may perhaps be used in conjunction with thrombolytic therapy that establishes reperfusion.     

Changes in xanthine and uric acid in rat brain after middle cerebral artery occlusion

Xanthine and uric acid, products of purine metabolism, were measured by reversed-phase high-performance liquid chromatography (HPLC) with electrochemical detection in rat forebrain following focal cerebral ischemia. Focal cerebral ischemia was induced in the rat by permanent occlusion of the left middle cerebral artery (MCA). Sprague-Dawley rats were anesthetized with halothane inhalation and left MCA was occluded via trans-retro-orbital approach. Normal and sham-operated rats were used as control animals. The animals were decapitated 2 (MCA = 5, Sham = 5), 4 (MCA = 7, Sham = 6), 8 (MCA = 5, Sham = 5), and 16 (MCA = 6, Sham = 6) hours or 1 (MCA = 5, Sham = 5), 2 (MCA = 6, Sham = 6), 7 (MCA = 7, Sham = 6), 14 (MCA = 6, Sham = 5), and 28 (MCA = 7, Sham = 5) days after the operation. The brains were removed and divided into right and left hemisphere. Each hemisphere was homogenized and centrifuged. The supernates were filtered with membrane filter. An aliquot of the filtrate was used for measurement of xanthine and uric acid in both of the ischemic and contralateral hemisphere by a HPLC system. In the normal group, xanthine and uric acid in the brain was 12.4 +/- 0.4 and 2.2 +/- 0.1 nmol/g tissue (mean +/- SEM), respectively. In the ischemic hemisphere, xanthine increased up to 57.7 +/- 5.2 nmol/g tissue 2 hours after MCA occlusion and reached a maximum value of 59.42 +/- 4.91 nmol/g tissue 4 hours following the induction of ischemia. Xanthine level was still high 8 hours after ischemia and then rapidly decreased to the normal value at day 2.(ABSTRACT TRUNCATED AT 250 WORDS)     

当归注射液抗慢性脑缺血大鼠认知功能损害的实验研究

目的 观察当归注射液对慢性脑缺血后认知功能改变及氧化应激损伤和胆碱能系统的影响,探讨当归注射液改善慢性脑缺血认知功能的作用及机制. 方法 50只Wistar大鼠采用随机数字表法分为假手术组(n=16)、生理盐水组(n=18)及当归治疗组(n=16),后两组大鼠制成双侧颈动脉结扎慢性脑缺血模型(即2VO模型),缺血4周、干预4周后水迷宫检测3组大鼠认知功能,并取脑皮质测定氧化产物及胆碱酯酶含量. 结果 慢性脑缺血后大鼠的空间记忆能力受损,定位航行实验中第4、5天当归治疗组的隐匿平台逃避潜伏期较假手术组有所增加,但较生理盐水组明显缩短(分别为22.53±1.27、27.67±1.34),3组之间差异有统计学意义(P<0.05);当归治疗组在空间探索试验中穿越平台的次数较生理盐水组增多(分别为1.25±0.78、0.56±0.63),在平台区的停留时间延长(分别为21.99±4.97、12.80±2.88),3组之间差异有统计学意义(P<0.05);当归治疗组AchE含量有所下降,但与假手术组比较差异仍有统计学意义(P<0.05),同时,MDA含量增高,SOD活力、抑制羟自由基能力及总抗氧化能力降低,与假手术组比较差异没有统计学意义(P>0.05). 结论 当归注射液能改善慢性脑缺血的认知功能损害,其作用可能与抑制氧化应激反应有关.     

NXY-059, a novel free radical trapping compound, reduces cortical infarction after permanent focal cerebral ischemia in the rat

Free radicals have gained wide acceptance as mediators of cerebral ischemic injury. It has previously been reported that a spin trap nitrone, alpha-phenyl-N-tert-butyl nitrone (PBN), can reduce infarct volumes in rats subjected to either permanent or transient focal cerebral ischemia. A recent study has demonstrated that NXY-059, a novel free radical trapping nitrone compound, has a neuroprotective effect against transient focal cerebral ischemia. This study was designed to determine the effect of NXY-059 in a rodent model of permanent focal cerebral ischemia. Male spontaneously hypertensive rats were subjected to permanent middle cerebral artery occlusion (MCAO) by placement of a microaneurysm clip on the middle cerebral artery (MCA). Animals were divided into three groups: (1) physiological saline given as a 1 ml/kg i.v. bolus administered 5 min post MCAO followed immediately by a continuous i.v. infusion of 0.5 ml/h of physiological saline for 24 h (n=10); (2) 30 mg/kg, 1 ml/kg, i.v. bolus of NXY-059 dissolved in physiological saline administered 5 min post MCAO followed immediately by a continuous i.v. infusion of 30 mg/kg/h, 0.5 ml/h, of NXY-059 for 24 h (n=9); (3) 60 mg/kg, 1 ml/kg, i.v. bolus of NXY-059 dissolved in physiological saline administered 5 min post MCAO followed immediately by a continuous i.v. infusion of 60 mg/kg/h, 0.5 ml/h, of NXY-059 for 24 h (n=12). Infarction was quantified after a survival period of 24 h. Differences in infarct volume were examined with one-way ANOVA following Dunnet's multiple comparison test. The percentage of cortical infarction in the saline control group was 22.6 +/- 6.8% (mean+/-S.D.) of contra-lateral hemisphere, and in the 30 mg/kg/h NXY-059-treated group was 17.4% +/- 6.8% (NS). Plasma concentration (microM/l) of NXY-059 in the 30 mg/kg/h group was 80.2 +/- 52.2 (n=9), while in the 60 mg/kg/h group plasma concentration (microM/l) of NXY-059 was 391.0 +/- 207.0 (n=10). Infarction in the 60 mg/kg/h NXY-059-treated group was significantly reduced (P=0.009) to 14.5 +/- 5%. Our preliminary data demonstrate that administration of NXY-059 (60 mg/kg/h for 24 h) ameliorates cortical infarction in rats subjected to permanent focal cerebral ischemia with 24 h survival.     

促红细胞生成素对大鼠蛛网膜下腔出血后血管痉挛的防治作用

目的 探讨促红细胞生成素（EPO）对大鼠蛛网膜下腔出血（SAH）后脑血管痉挛（CVS）的影响及其机制。方法 将60只成年SD大鼠随机分为正常组（6只）、假手术组（18只）、SAH组（18只）、EPO组（18只）;假手术组、SAH组合EPO组根据取材时间有分为1、3、7 d三亚组,每亚组6只。采用枕大池二次注血法建立SAH模型。EPO组建模成功后30 min内腹腔注射EPO（3 000 IU/kg,1次/d）。建模成功后1、3、7 d采用取材基底动脉行HE染色测量基底动脉管径及管壁厚度,采用免疫组化检测基底动脉血管壁核转录因子-κB（NF-κB）及内皮细胞型一氧化碳合酶（eNOS）的表达。结果 SAH后1、3、7 d,假手术组基底动脉管径、管壁厚度、NF-κB和eNOS表达水平与正常组无统计学差异（P>0.05）;与假手术组相比,SAH组各时间点基底动脉管径均明显减小（P<0.05）,管壁厚度均明显增加（P<0.05）,NF-κB表达水平均明显增加（P<0.05）,eNOS表达水平均明显降低（P<0.05）;与SAH组相比,EPO组基底动脉管径、管壁厚度均明显改善（P<0.05）,NF-κB表达水平均明显降低（P<0.05）,eNOS表达水平均明显增加。结论 EPO能够显著改善大鼠SAH后CVS,机制可能是通过上调eNOS的表达、抑制NF-κB的表达来实现的。     

Neuroprotective effect of a heat shock protein inducer, geranylgeranylacetone in permanent focal cerebral ischemia

Previous studies have strongly suggested that heat shock protein 70 (HSP70) has protective effects in ischemia/reperfusion in tissues such as brain, heart, and liver. This study was performed to assess the efficacy of the HSP70 inducer geranylgeranylacetone (GGA) in experiments involving permanent middle cerebral artery (MCA) occlusion. Male Balb/c mice were subjected to permanent MCA occlusion by direct occlusion through small craniectomy. Vehicle or GGA (200 or 1000 mg/kg) was injected intraperitoneally 1 h prior to the onset of ischemia. Infarct volumes were evaluated at 24 h of ischemia by using 2,3,5-triphenyltetrazolium chloride (TTC) staining. The effect of GGA on the induction of HSP70 was studied at 3 h after ischemia with fluorescence immunocytochemistry. The percentage of infarct volume in the control mice (n=10) was 23.0+/-4.0% (mean+/-SD) of the contralateral hemisphere, while those in the treated groups were 22.6+/-7.3% (200 mg/kg group; n=5, P>0.05) and 15.7+/-3.8% (1000 mg/kg group; n=5, P<0.05). Pretreatments with 1000 mg/kg of GGA enhanced the ischemia-related induction of HSP in the neurons and astrocytes in the boundary zone of infarct. The results demonstrate that GGA significantly reduces infarct volume due to permanent MCA occlusion when given 1 h prior to the induction of ischemia.