单次9小时高压氧超早期治疗对大鼠脑梗死体积的影响

目的 本研究主要观察高压氧（HBO）单次9 h超早期治疗对永久性大脑中动脉阻塞（MCAO）大鼠脑梗死体积的影响。方法 制作SD大鼠永久性MCAO模型,随机分为对照组、HBO组,HBO组大鼠于模型制备成功后3 h予单次9 h HBO治疗,压力0.2 MPa。模型成功后13 h、5 d,分别将大鼠脑组织进行2,3,5苯四氮唑（TTC）染色测定梗死体积,免疫组织化学染色测定脑组织中血管内皮生长因子（VEGF）的表达情况。结果 （1）13 h时,两组大鼠脑梗死体积相差不大（P >0.05）;5 d时,对照组大鼠脑梗死体积较13 h时增大（P <0.05）,而HBO组变化不大（P >0.05）,组间比较,HBO组较对照组脑梗死体积缩小（P <0.05）。（2）13 h时,对照组和HBO组VEGF均有表达,两组间差异无统计学意义（P >0.05）;5 d时,对照组VEGF表达较13 h时明显减少（P <0.01）,而HBO组VEGF表达明显高于13 h,而且显著高于对照组5 d水平（P <0.01）。结论 单次9 h HBO超早期治疗可缩小大鼠脑梗死体积,其机制可能与HBO提高内源性VEGF表达有关。     

Effect of large dose hyperbaric oxygenation therapy on prognosis and oxidative stress of acute permanent cerebral ischemic stroke in rats

OBJECTIVE: To evaluate the therapeutic effect and the oxidative stress effect of 9 and 18 hour hyperbaric oxygenation therapy (HBOT) protocols on the earliest stage of acute permanent middle cerebral artery occlusion (MCAO) in rats. METHODS: The permanent MCAO model of rats was used. The animals were randomly divided into 9 and 18 hour HBOT groups, as well as a control group. MAIN OUTCOME MEASURES: (1) The Garcia neurological grading system was used to assess the therapeutic effect of hyperbaric oxygenation therapy; (2) the infarct volume was calculated with the 2,3,5-triphenyltetrazolium chloride (TTC) pathologic staining and NIH Image J software 24 and 120 hours after MCAO; (3) the level of reactive oxygen species determined by superoxide dismutase (SOD), malondialdehyde (MDA) and nitric oxide (NO) in ischemic brain tissue were separately examined at the 18, 48 and 120 hour post-ischemia time points using spectrophotometry. RESULTS: (1) There were significant improvements in the neurobehavioral outcome of the rats in the 9 and the 18 hour groups, as compared with rats from the control group (p<0.01); (2) cerebral infarct volume decreased 63-64% in the rats of 9 hour group and 51-66% in the 18 hour group at the 24 and 120 hour time points, as compared with that of the control group; (3) the SOD levels of the 9 and 18 hour groups were remarkably lower than those of control group after both 18 and 48 hours (p<0.01 and p<0.05); (4) the MDA level of the 9 and 18 hour groups were both remarkably lower than the control groups, especially at 18 hours (p<0.05). Meanwhile, the MDA level in the 9 hour group was remarkably lower than both the 18 hour group and the control group (p<0.01 and p<0.05); (5) the level of NO in both hyperbaric oxygenation therapy groups were remarkably higher than that of the control at 18 and 48 hour time points (p<0.01). While the level in 18 hour group was remarkably lower than that of 9 hour group at 18 hour time point (p<0.05). At the 120 hour mark, the NO levels were basically the same in all the three groups. CONCLUSIONS: (1) The two protocols of large dose hyperbaric oxygenation therapy are highly efficient in reducing infarct volume and improving neurobehavioral outcome in permanent MCAO rats within the earliest stages of stroke; (2) increased duration of hyperbaric oxygenation therapy does not appear to equate to improved outcomes; in fact, the longer duration may aggravate the oxidative stress in ischemic tissue.     

大剂量高压氧超早期治疗对局部脑梗死大鼠细胞凋亡的影响

目的 观察大剂量高压氧（hyperbaric oxygenation,HBO）超早期治疗对永久性大脑中动脉阻塞
（middle cerebral artery occlusion,MCAO）大鼠细胞凋亡的影响。
方法 制作SD大鼠永久性MCAO模型,随机分为对照组（n =36）和HBO组（n =36）,HBO组大鼠于模型
制备成功后3 h予单次9 h HBO治疗,压力0.2 MPa。于模型成功后3 h、13 h、72 h,行大鼠Garcia神经功
能评分,于13 h、72 h分别将大鼠脑组织进行2,3,5苯四氮唑（tetrazolium chloride,TTC）染色测定梗
死容积百分比,应用脱氧核糖核苷酸末端转移酶介导的缺口末端标记法（terminal-deoxynucleotidyl
transferase mediated nick end labeling,TUNEL）检测细胞凋亡,流式细胞仪检测线粒体膜电位。
结果 ①两组大鼠在MCAO 13 h时（P均=0.007）和72 h时（P均＜0.001）均较同组MCAO 3 h时神经功
能明显改善,但各时间点两组间神经功能无显著差异。②13 h时,两组大鼠脑梗死容积比无显著差异;
72 h时,对照组大鼠脑梗死容积比较13 h时增大（P =0.02）,而HBO组无显著变化,HBO组较对照组脑
梗死容积比小（P =0.02）。③HBO组及对照组在13 h、72 h均可见凋亡细胞,13 h时HBO组凋亡细胞数少
于对照组（P =0.04）。④大鼠MCAO后线粒体膜电位降低,HBO组在13 h、72 h的线粒体膜电位均高于对
照组,差异有显著性（P均＜0.001）。
结论 大剂量HBO超早期治疗可缩小大鼠脑梗死容积,抑制线粒体膜电位降低,进而减少细胞凋亡
可能是高压氧治疗脑梗死的机制之一。     

高压氧预处理减少局灶性脑缺血后泛素化蛋白聚集

目的探讨泛素-蛋白酶体系统在重复高压氧（HBO）预处理导致的脑缺血耐受中所起的作用。方法采用大脑中动脉阻闭（MCAO）制备大鼠局灶性脑缺血模型,将33只SD大鼠随机分为假手术组（Sham）组、MCAO组和HBO组,分别观察各组大鼠脑梗死灶的大小和神经功能学评分,并用免疫组织化学染色检测再灌注2h、24h时相点大鼠脑组织CA1区异常泛素化蛋白聚集的变化。结果 HBO组脑梗死容积小于MCAO组,差异有统计学意义（P〈0.05）,其神经功能学评分也明显优于MCAO组（P〈0.05）。再灌注各时相点,HBO组泛素化蛋白聚集明显少于MCAO组（P〈0.05）。结论高压氧预处理所诱导的脑缺血耐受的机制可能与泛素化蛋白聚集降低有关。     

Reduced infarct volume and differential effects on glial cell activation after hyperbaric oxygen treatment in rat permanent focal cerebral ischaemia

Permanent middle cerebral artery occlusion (MCAO) causes neurodegeneration and a robust activation of glial cells primarily in sensorimotor brain regions of rats. It has been shown that hyperbaric oxygen (HBO) increases oxygen supply to ischaemic areas and reduces neuronal cell loss. The effects of HBO treatment on microgliosis and astrogliosis in permanent cerebral ischaemia have not been addressed so far, but might be critical for neurodegeneration and neuroprotection, respectively. Therefore, we used spontaneously hypertensive rats with permanent MCAO to investigate the time window to start HBO and to compare the effects of different HBO treatment frequencies on infarct volume and on differences with regard to microgliosis and astrogliosis. Seven days after MCAO the infarct volume was calculated from Nissl-stained brain sections by image analysis. HBO significantly decreased the infarct volume when used as early as 15, 90 or 180 min post-MCAO by 24%, 16% and 13%, respectively, in the single-treatment group. Repetitive HBO treatment (first HBO session 90 min after MCAO) was not effective. Microglial cells and astrocytes were detected by cytochemical fluorescent labelling and confocal laser scanning microscopy. In the single-treatment group we observed significantly higher astrocyte immunoreactivity but decreased microglial density in the peri-infarct region. These effects of HBO treatment on glial cells were not present in rats where HBO did not reduce the infarct volume (360 min after MCAO). Our data indicate that HBO-induced suppression of microgliosis and aggravated response of astrocytes might contribute to the reported beneficial effects of early HBO treatment in cerebral ischaemia.     

Hyperbaric oxygen treatment induces dynamic ATPase activity changes in the rat brain following transient global cerebral ischemia-reperfusion*

BACKGROUND： Energy depletion, induced by ischemia or hypoxia, is one of the first events in neuronal injury. OBJECTIVE： To investigate the dynamic changes of Na^＋-K^＋-ATPase and Ca^2＋-ATPase activity in the rat brain following transient global cerebral ischemia-reperfusion （IR）, as well as the effects of hyperbaric oxygen （HBO） treatment. DESIGN, TIME AND SETTING： A randomized and controlled animal study was performed in the Department of Biochemistry and Molecular Biology, Capital Medical University between February and December 2006. MATERIALS： Clean-grade, female, Sprague Dawley rats were provided by the Animal Research Department of Capital Medical University （License number： SYXK11-00-0047）. Na^＋-K^＋-ATPase and Ca^2＋-ATPase kits were provided by Nanjing Jiancheng Bioengineering Institute （Nanjing, China）. A hyperbaric oxygen chamber （DWC150-300） was supplied by Shanghai 701 Medical Oxygen Chamber Factory （Shanghai, China）. METHODS： Sixty-three rats were randomly divided into nine groups： sham operated group （sham-O） as control, groups of IR, and groups treated with hyperbaric oxygen （HBO） after IR. Animal from the IR and HBO groups were sacrificed after four different survival intervals of 6, 24, 48 and 96 hours, respectively. Each group consisted of seven rats. The rats of HBO groups were placed into the hyperbaric chamber. The HBO chamber was flushed with pure oxygen for 5 minutes, followed by a gradual rise in pressure over 5 minutes and stabilization at 0.2 MPa. Then, pure oxygen was supplied for 45 minutes in stabilized pressure, followed by gradually reduced pressure over 15 minutes. The rats of the 6-h HBO group were placed into the HBO chamber following reperfusion for 3 hours on the first day, which was repeated on three consecutive days, always at the same time. Rats in the sham-O group and IR group remained under normal atmospheric pressure. MAIN OUTCOME MEASURES： The Na^＋-K^＋-ATPase and Ca^2＋-ATPase activity in rat brain homogenate     

高压氧治疗对局灶性脑梗死大鼠的神经保护作用

目的 观察单次9 h高压氧（hyp erbaric oxygen，HBO）治疗对局灶性脑梗死大鼠凋亡诱导因子
（apoptosis-inducing factor，AIF）、线粒体膜电位（mitochondrial membrane potential，MMPo）的影响，探讨
HBO治疗的神经保护作用。
方法 108只SD大鼠制作永久性大脑中动脉闭塞模型，随机分为对照组和HBO组，每组各54只。造
模成功3 h后，HBO组实行HBO干预，压力0.2 MPa持续9 h，对照组呼吸常压空气。采用Garcia评分评估
大鼠神经功能，比较两组造模后13 h、24 h和72 h神经功能改善情况，并在各时间点检测大鼠缺血半
暗带脑组织凋亡细胞数、线粒体和细胞核AIF表达及MMPo水平。
结果 ①神经功能评分：HBO组13 h（P <0.001）、24 h（P =0.04）神经功能评分改善比对照组更明显。
②凋亡细胞数：HBO组13 h、24 h凋亡细胞数较对照组更少（均P <0.001）。③AIF在线粒体和细胞核的
表达：13 h、24 h、72 h各时间点HBO组AI F在线粒体的表达均较对照组多（均P <0.001）；各时间点HBO
组AIF在细胞核的表达均较对照组少（均P <0.001）。④MMPo：各时间点HBO组MMPo均高于对照组（均
P <0.001）。
结论 HBO治疗可改善大鼠神经功能，稳定MMPo，抑制AIF由线粒体向细胞核转移可能是其神经保
护作用的机制之一。     

高压氧对大鼠脑缺血再灌注损伤的保护作用及其对低氧诱导因子-1a的影响

目的探讨高压氧(HBO)对脑缺血再灌注大鼠神经元的保护作用及其对低氧诱导因子(HIF)-1a的影响。方法选取SD大鼠30只,随机分为假手术组、模型组、治疗组,每组10只。采用线栓法建立脑缺血再灌注模型,采用TTC染色观察脑缺血再灌注大鼠梗死灶体积;行为学评分观察其神经功能缺损;蛋白印迹法观察HIF-1a的表达及HBO干预后的改变。结果与模型组相比,治疗组大鼠脑梗死灶体积,行为学评分及HIF-1a的表达均明显减少(P<0.05);与假手术组相比,治疗组HIF-1a的表达无明显增加(P>0.05)。结论HBO治疗能抑制组织HIF-1a的表达,从而对大鼠脑缺血再灌注损伤具有保护作用。     

高压氧治疗对大鼠脑挫裂伤后细胞凋亡的影响

目的 探讨高压氧对大鼠脑挫裂伤的治疗作用与对细胞凋亡的影响之问的关系。方法 制作SD大鼠自由落体脑挫裂伤模型，设立高压氧治疗组和对照组，分别应用透射电镜、原位末端标记法(TUNEL)和流式细胞技术对各组动物挫伤灶旁和海马结构的细胞凋亡情况进行检测。结果 脑外伤后存在细胞凋亡，细胞凋亡的发生在伤后24h达到高峰，高压氧治疗组在伤后24h和48h细胞凋亡发生率显著低于相应的对照组(氏0．05)。结论 高压氧治疗能显著减少脑损伤后细胞凋亡的发生，这很可能是高压氧对创伤性脑损伤的治疗作用的重要机制。     

高压氧治疗对局灶性脑梗死大鼠的神经保护作用

目的 观察单次9 h高压氧（hyp erbaric oxygen,HBO）治疗对局灶性脑梗死大鼠凋亡诱导因子 （apoptosis-inducing factor,AIF）、线粒体膜电位（mitochondrial membrane potential,MMPo）的影响,探讨 HBO治疗的神经保护作用。 方法 108只SD大鼠制作永久性大脑中动脉闭塞模型,随机分为对照组和HBO组,每组各54只。造 模成功3 h后,HBO组实行HBO干预,压力0.2 MPa持续9 h,对照组呼吸常压空气。采用Garcia评分评估 大鼠神经功能,比较两组造模后13 h、24 h和72 h神经功能改善情况,并在各时间点检测大鼠缺血半 暗带脑组织凋亡细胞数、线粒体和细胞核AIF表达及MMPo水平。 结果 ①神经功能评分：HBO组13 h（P <0.001）、24 h（P =0.04）神经功能评分改善比对照组更明显。 ②凋亡细胞数：HBO组13 h、24 h凋亡细胞数较对照组更少（均P <0.001）。③AIF在线粒体和细胞核的 表达：13 h、24 h、72 h各时间点HBO组AI F在线粒体的表达均较对照组多（均P <0.001）;各时间点HBO 组AIF在细胞核的表达均较对照组少（均P <0.001）。④MMPo：各时间点HBO组MMPo均高于对照组（均 P <0.001）。 结论 HBO治疗可改善大鼠神经功能,稳定MMPo,抑制AIF由线粒体向细胞核转移可能是其神经保 护作用的机制之一。     

高压氧预适应对大鼠高原颅脑损伤的作用研究

目的探讨高压氧（HBO）预适应对高原颅脑损伤（TBI）的神经保护作用。方法将78只SD大鼠随机分为平原组、高原组和高压氧预适应组，各组按Feeney自由落体撞击法制作TBI模型，并通过低压氧舱模拟高原环境。采用Longa评分法进行神经功能缺损评分，Moor DRT4激光多普勒血流监测仪和LICOX CMP组织氧分压监测仪分别监测伤区局部脑血流（rCBF）和局部脑组织氧分压（PbtiO2）变化，利用光镜观察伤区脑组织的病理学改变。结果伤后24h高原组较平原组神经功能缺损评分上升。rCBF和PbtiO2下降，病理损伤加重；高压氧预适应组较高原组神经功能缺损评分下降（P〈0.05），rCBF和PbtiO2升高（均为P〈0.05）病理损伤减轻。结论高压氧预适应可诱导对高原颅脑损伤的神经保护作用改善神经功能。     

高压氧对大鼠颅脑爆震伤后皮层脑组织自噬与凋亡变化的影响

目的 观察高压氧治疗颅脑爆震伤后大鼠皮层脑组织自噬与凋亡表达的变化,探讨高压氧对脑细胞自噬和凋亡表达的影响及其意义. 方法 SD大鼠54只按照随机数字表法分为对照组(n=6)、爆震伤组(n=24)及爆震伤后高压氧治疗组(治疗组,n=24),对照组不进行致伤,爆震伤组和治疗组用600 mg TNT电雷管在大鼠头部正上方垂直距离12 cm处爆炸致伤,爆震伤组伤后不做任何治疗,治疗组分别于伤后3 h、22h及以后每天同一时间行高压氧处理,爆震伤组和治疗组分别于6 h、24 h、3 d、7 d采用RT-PCR和Western blotting检测皮层脑组织中Beclin-1和caspase-3的表达情况. 结果 与对照组相比,爆震伤组及治疗组各个时间点的Beclin-1和caspase-3表达均明显增加,差异有统计学意义(P＜0.05);同一时间点上,治疗组中Beclin-1和caspase-3表达则较爆震伤组明显减少,差异有统计学意义(P＜0.05). 结论 高压氧降低脑细胞的自噬和凋亡表达,此可能是其治疗颅脑损伤的机制之一.     

Neuroprotective effects of hyperbaric oxygen treatment in experimental focal cerebral ischemia are associated with reduced brain leukocyte myeloperoxidase activity

OBJECTIVE: Hyperbaric oxygen (HBO) reduces cerebral infarct size after middle cerebral artery occlusion (MCAO) in rats through an unknown mechanism. In other forms of injury, cellular protection with HBO is associated with diminished infiltration of polymorphonuclear neutrophils (PMN). We hypothesized that HBO given prior to or after MCAO reduces PMN infiltration into the brain, and that decreased PMN infiltration is associated with improved functional and anatomic outcome. METHODS: Forty rats underwent MCAO and were randomized to pretreatment with HBO (3 ATA) immediately prior to (n=13), or posttreatment immediately after surgery (n=12), or to control (air 1 ATA) (n=15). Five rats underwent sham surgery. Neurologic outcome was measured at 24 h in all animals. Brain myeloperoxidase (MPO) activity (n=22) and infarct volume (n=23) were determined. RESULTS: MPO activity was significantly higher in controls (mean 0.28, 95% C.I. 0.17-0.38) than in the HBO pretreatment group (0.12, 0.08-0.16), HBO posttreatment group (0.16, 0.13-0.19), and the sham group (0.02, -0.02 to 0.05). HBO treated animals also had better neurologic outcomes (pretreatment 1.5, 0.9-2.1, posttreatment 2.6, 2.0-3.2) and smaller infarcts (pretreatment 27%, 18-37%, posttreatment 28%, 19-37%) than controls (neurologic outcome 3.7, 3.1-4.4, infarct volume 39%, 30-48%). Neurologic outcomes correlate better with MPO activity (R(2)=0.75) than with infarct volume (R(2)=0.25). CONCLUSION: These data confirm the neuroprotective effects of HBO in cerebral ischemia and suggest that the mechanism of this action may involve inhibition of PMN infiltration in the injured brain.     

Hyperbaric oxygen induces rapid protection against focal cerebral ischemia

BACKGROUND AND PURPOSE: The timing and mechanisms of protection by hyperbaric oxygen (HBO) in cerebral ischemia have only been partially elucidated. We monitored the early in vivo effects of HBO after 2 h transient focal ischemia using repetitive MRI. METHODS: Wistar rats underwent filament occlusion of the middle cerebral artery (MCAO). 40 min after MCAO, rats were placed in a HBO chamber and breathed either 100% O(2) at 3.0 atmospheres absolute (ata; n = 24) or at 1.0 ata (control; n = 24) for 1 h. Diffusion, perfusion and T2-weighted MR-images were obtained after 15 min and 3, 6 and 24 h of reperfusion. In 6 axial MR slices, volume of abnormal diffusion and T2w signals were measured in the ischemic hemisphere. Furthermore, hemispheric mean apparent diffusion coefficient- (ADC) and T2 values were calculated for statistical analysis. RESULTS: HBO significantly reduced volume of abnormal DWI signal beginning immediately after reperfusion (control: 92 +/- 28 mm(3); HBO: 64 +/- 17) and lesion size on T2w (control: 375 +/- 91 mm(3); HBO: 225 +/- 39) after 24 h. Correspondingly, mean ADC levels were lower and T2 values higher in the ischemic hemisphere in the control group. HBO reduced histological infarct size at 24 h. CONCLUSION: High-dose intraischemic HBO therapy has an immediate protective on the brain which is superior to normobaric oxygen.     

Delayed and multiple hyperbaric oxygen treatments expand therapeutic window in rat focal cerebral ischemic model

Although the brain-protective effect of single, early applications of hyperbaric oxygen (HBO) has been reported in acute ischemic stroke models, few studies have reported the long-term effect—especially after multiple HBO applications. This study employed delayed, multiple HBO treatments and evaluated cerebral infarction and neurological functional recovery for 4 weeks after transient focal ischemia. Adult male Sprague-Dawley rats were subjected to middle cerebral artery occlusion/reperfusion (MCAO/R) and were subsequently exposed to HBO (2.5 atmospheres absolute [ATA]) for 2 hours per day. HBO was administered at either 6 or 24 hours after MCAO/R and was repeated daily for 6 days. Rat behavior was scored to evaluate neurological deficits. The brains were removed for histological analysis of the infarct ratio at 1 and 4 weeks. Rats with HBO delayed for 6 or 24 hours following MCAO/R displayed a significant decrease of infarct ratio and amelioration of neurological deficits compared to the untreated group. This study suggests that delayed, but multiple, HBO treatments can improve neurological evaluation and reduce cerebral infarction.     

大剂量高压氧治疗对脑梗死大鼠组织核因子κB的影响

【摘要】 目的 探讨大剂量高压氧治疗方案对永久性大脑中动脉闭塞大鼠的疗效以及高压氧对大鼠梗死部位周围脑组织核因子κB（nuclear factor-κB,NF-κB）影响。 方法 制备雄性Sprague-Dawley大鼠永久性大脑中动脉闭塞模型,随机分为高压氧组和对照组,每组32只,另设立伪手术组。使用Garcia神经行为学评分方法分别在术后24 h、5 d对大鼠进行神经行为学评分;应用2,3,5-三苯基氯化四氮唑（2,3,5-triphenyltetrazolium chlorid,TTC）方法对脑组织进行染色,观察24 h、5 d时大鼠脑组织梗死容积;取梗死部位周围脑组织,采用凝胶电泳迁移实验（electrophoretic mobility shift assay,EMSA）方法检测术后24 h、5 d时的NF-κB脱氧核糖核酸（deoxyribonucleic acid,DNA）结合活性。比较三组间上述指标的差异。 结果 术后24 h高压氧组神经行为学评分高于对照组［（13.33±1.53）vs（10.33±0.58）,P<0.001］。术后24 h高压氧组梗死容积小于对照组［（139.73±33.59）vs（203.02±57.66）,P=0.008］。术后5 d高压氧组梗死部位周围脑组织NF-κB活性低于对照组［（16.01±4.56）vs（50.28±9.13）,P=0.035］。 结论 大剂量高压氧治疗方案在脑梗死后24 h内具有脑保护作用。大剂量高压氧可降低大鼠梗死部位周围脑组织NF-κB DNA结合活性。     

高压氧预处理可对大鼠局灶性脑缺血再灌注损伤的保护作用

目的研究短期高压氧预处理后是否可减轻大鼠局灶性脑缺血再灌注损伤。方法选取成年雄性Wister大鼠,采用连续5d,每天1次,3.0ATA,100%O2高压氧(HBO)预处理,每次60min,末次预处理后24h,运用改良的经典线栓法制作MCAO模型,再灌注2h。将实验大鼠分为假手术组、MCAO组、HBO+MCAO组(n=5)。造模后24h观察各组动物的一般精神状态及体重变化情况、用Rogers DC and Hunter AJ描述的神经功能7分评分法对神经功能损伤进行评估,TTC染色测梗死面积,并对脑组织进行石蜡切片,行Nissl、TUNEL染色,利用显微镜对神经细胞进行计数。结果假手术组无神经功能缺失,TTC染色未见梗死灶,镜下观察未见坏死细胞。MCAO组和HBO+MCAO组均有不同程度的神经功能缺损,且HBO+MCAO组神经功能缺失较MCAO组轻;TTC染色MCAO组的梗死面积明显大于HBO+MCAO组;镜下观察,MCAO组梗死区内尼氏小体明显少于HBO+MCAO组。结论短期高压氧预处理后可减轻大鼠局灶性脑缺血再灌注损伤。     

血管内尼龙线栓塞大鼠大脑中动脉局灶性脑缺血模型的改进

目的 确立更规范统一的制作大鼠局灶性脑缺血模型方法，使脑梗死体积更加稳定。方法 对24只大鼠使用液态硅胶涂层尼龙线栓塞大脑中动脉，分别缺血l，2，6和24h后再灌注24h，监测缺血侧局部脑血流，测定脑梗死体积及脑水肿程度。结果 缺血后所有大鼠局部脑血流均降到缺血前基值的25％以下，TTC染色显示所有动物在缺血侧皮质和尾状核均有明显的梗死灶和缺血，缺血1h组梗死体积与缺血2h以上组有显性差异，缺血2h以上各组之间梗死体积无显性差异；各组脑水肿程度无显性差异。结论 应用硅胶涂层尼龙线结合局部脑血流监测，缺血2h以上同时予以血流监测，可制作梗死体积稳定的大鼠局灶性脑缺血模型。     

高压氧联合骨髓间充质干细胞移植修复缺氧缺血性脑损伤

背景：单纯骨髓间充质干细胞移植对脑梗死组织的修复作用并不理想,需要结合药物及生物工程材料等手段进行综合治疗。 目的：验证高压氧结合骨髓间充质干细胞移植修复大鼠缺氧缺血性脑损伤的效果。 方法：体外培养大鼠骨髓间充质干细胞。应用线栓法建立大脑中动脉阻塞大鼠模型,按随机区组法分为3组,即对照组、骨髓间充质干细胞移植组及高压氧+骨髓间充质干细胞移植组。静脉移植后24 h,3 d及伤后1,2 周行Longa行为学评分,检测神经功能的损伤情况。移植2周后,应用RT-PCR法测定生长相关蛋白43 mRNA的表达,并以BrdU免疫组化和苏木精-伊红染色行梗死处组织学检查以证实恢复程度。 结果与结论：移植后1周,高压氧+骨髓间充质干细胞移植组大鼠神经功能障碍评分低于骨髓间充质干细胞移植组,骨髓间充质干细胞移植组低于对照组(P < 0.05)。2周后脑梗死周围组织生长相关蛋白43 mRNA的表达高压氧+骨髓间充质干细胞移植组高于骨髓间充质干细胞移植组,骨髓间充质干细胞移植组高于对照组(P < 0.05)。BrdU免疫组化和苏木精-伊红切片中的神经元数量高压氧+骨髓间充质干细胞移植组多于骨髓间充质干细胞移植组,骨髓间充质干细胞移植组多于对照组(P < 0.05)。提示高压氧联合骨髓间充质干细胞静脉移植治疗大鼠缺氧缺血性脑损伤可明显改善大鼠的神经功能,效果优于单纯骨髓间充质干细胞移植。     

Mild hypothermia effects on matrix metalloproteinase-9 expression in the perihematomal region of rats following experimental intracerebral hemorrhage

BACKGROUND:Matrix metalloproteinase-9(MMP-9)expression increases with intracerebral hemorrhage,and participates in the pathophysiological processes of secondary brain injury after intracerebral hemorrhage.OBJECTIVE:To investigate the effects of mild hypothermia on MMP-9 expression and brain edema in the perihematomal region of experimental intracerebral hemorrhage rats.DESIGN,TIME AND SETTING:The randomized,controlled experiment was performed at the Central Laboratory of Shandong Provincial Hospital between May and September 2007.MATERIALS:Seventy-two,Wistar,male rats,12-weeks old,were used for this study.Rabbit anti-MMP-9 primary antibody was purchased from Boster,China.METHODS:Wistar rats were equally and randomly divided into normothermia and mild hypothermia groups.The two groups each comprised control,6-hour intracerebral hemorrhage,24-hour intracerebral hemorrhage,48-hour intracerebral hemorrhage,72-hour intracerebral hemorrhage,and 1-week intracerebral hemorrhage subgroups,with six rats in each subgroup.Rat models of intracerebral hemorrhage were established by irtjecting 100 μL of autologous blood into the rat caudate nucleus.Rats in the mild hypothermia group received four hours of local mild hypothermia immediately following the injection.Intracerebral temperature was maintained at(33±0.5)℃.Subsequently,intracerebral temperature was spontaneously recovered at 25℃.Rats in the control subgroup were not injected with autologous blood and received only with intracerebral hemorrhage.MAIN OUTCOME MEASURES:Brain water content and MMP-9 expression surrounding the hematoma region.RESULTS:MMP-9 expression increased at 6 hours,and brain edema reached a peak at 48 hours after intracerebral hemorrhage.MMP-9 expression was significantly decreased in the mild hypothermia group compared with the normothermia group at each time point (P<0.05).CONCLUSION:Mild hypothermia can significantly inhibit MMP-9 overexpression and relieve brain edema following intracerebral hemorrhage.