高压氧预处理对大鼠脑缺血再灌注损伤的保护作用及对其海马BDNF和GDNF基因表达的影响

目的:探讨高压氧预处理(Hyperbaric oxygen preconditioning, HBO-PC)对大鼠脑缺血再灌注损伤的保护作用及对其海马脑源性神经营养因子(brain-derived neurotrophic factor, BDNF)、胶质细胞源性神经营养因子(glialcellline-derivedneurotrophicfactor,GDNF)基因表达的影响。方法:将32只SD雄性大鼠随机分为对照组(Sham组)、高压氧对照组(HBO组)、模型组(MCAO组)、高压氧预处理+模型组(HBO+MCAO组),对HBO组和HBO+MCAO组连续给予高压氧预处理5天,随后对MCAO组和HBO+MCAO组进行右侧颈内动脉栓线术,建立大脑中动脉闭塞(middle cerebral artery occlusion, MCAO)模型,其他两组行假手术,于术后第7天对各组大鼠进行Morris水迷宫行为学检测和神经功能评分,检测结束后处死大鼠,进行神经功能缺损评分及氯化三苯基四氮唑(2,3,5-triphenyltetrazolium chloride, TTC)染色;通过蛋白免疫印迹法(Western Blot)检测大鼠海马组织BDNF和GDNF的基因表达情况。结果:(1)神经功能评分提示:Sham组和HBO组均未出现神经功能障碍,MCAO组大鼠出现明显的神经功能障碍,MCAO+HBO组神经功能评分明显高于MCAO组(P0.05)。(2)TTC检测提示:Sham组和HBO组脑组织损伤一侧均未出现梗死灶,MCAO组出现较大的梗死面积比(25.45±8.75)%,MCAO+HBO组的梗死面积比(18.84±10.55)显著小于MCAO组,差异具有统计学意义(P 0.05)。(3)Western Blot检测显示:MCAO组BDNF与GDNF基因表达水平显著低于Sham组和HBO组,差异具有统计学意义(P 0.05),而MCAO+HBO组可以逆转这一效应,差异具有统计学意义(P 0.05)。结论:高压氧预处理可以通过调节BDNF、GDNF基因表达,改善MCAO模型大鼠神经功能和认知水平,发挥神经保护作用。     

海马Sirt1在高压氧预处理改善异氟醚诱导老龄小鼠认知功能障碍中的作用

摘要 目的：通过shRNA抑制沉默信息调节因子1（sirtuin 1,Sirt1）基因表达,研究Sirt1在高压氧预处理改善异氟醚（isoflurane,ISO）诱导小鼠认知功能障碍中的作用及其对小鼠海马BDNF、GDNF基因表达的影响。方法： 将64只C57雄性小鼠随机分为假手术组（Sham组）、高压氧组（HBO组）、异氟醚组（ISO组）、高压氧预处理+异氟醚组（HBO + ISO组）;以及对照组（NS组）、Sirt1抑制组（sh-Sirt1组）、对照+高压氧预处理组（NS + HBO组）和Sirt1抑制+高压氧预处理组（sh-Sirt1 + HBO组）,每组8只。经慢病毒转染以及ISO末次暴露24小时后进行认知功能测试（Morris水迷宫测试）,随后处死小鼠,利用实时荧光定量聚合酶链反应（RT-qPCR）检测海马BDNF和GDNF的mRNA表达情况。结果：（1）异氟醚可以导致明显的认知功能障碍,与Sham组相比,ISO组靶象限探索时间百分比显著减低（P<0.01）,ISO组小鼠海马BDNF和GDNF mRNA表达水平显著下降（P<0.01）。（2）高压氧预处理可以改善POCD小鼠的认知功能障碍,ISO + HBO组靶象限探索时间百分比显著高于ISO组（P<0.05）,ISO + HBO组小鼠海马BDNF（P<0.05）和GDNF（P<0.01）mRNA表达水平显著升高。（3）高压氧预处理可以显著增加POCD小鼠海马BDNF（P<0.01）和GDNF（P<0.05）mRNA表达水平,慢病毒介导shRNA靶向下调Sirt1可以逆转高压氧预处理对POCD小鼠海马BDNF（P<0.05）和GDNF（P<0.01）mRNA表达水平的改变。结论：高压氧预处理是治疗POCD的有效方法,Sirt1可能是POCD治疗的潜在分子靶点。     

高压氧对脑 因再灌注海马CA1区神经元调亡作用的研究

目的和方法：应用TUNEL检测技术,对沙土鼠前脑缺血20min后再灌注3d模型,用HBO治疗连续3d。观察HBO作用下海马CA1区神经元凋亡变化,研讨HBO对脑缺血再灌注损伤的疗效及其机理,为临床应用HBO治疗疾病提供理论依据。结果：沙土鼠脑缺血再灌注3d后海马CA1区大量神经元凋亡,HBO治疗组凋亡细胞数明显减少（P＜0.01）,并以0.25MPa HBO治疗组为佳。结论：HBO治疗对海巴神经元损伤有保护作用,减少神经元凋亡,为高压氧治疗缺血性损伤有疗效机理之一。     

自噬在高压氧预处理预防脊髓缺血再灌注损伤中 的作用机制研究*

目的:研究自噬在高压氧预处理预防脊髓缺血再灌注损伤中的机制。方法:新生大鼠脊髓神经元原代培养,分为对照组(氧糖剥夺)和高压氧(HBO)预处理组。通过应用免疫组织化学、Western blot分析两组LC3-Ⅱ与凋亡相关分子Beclin-1,Bcl-2,Casp-ase-3的表达变化。结果:发现重复高压氧预处理对氧糖剥夺诱导原代培养的脊髓神经元损伤具有明显的保护作用。免疫组化和Western blot显示与对照组相比高压氧预处理显著增加脊髓神经元细胞Bcl-2的表达,降低Beclin-1,Caspase-3以及自噬的特异性标记蛋白LC3-Ⅱ的表达。氧糖剥夺后对照组与高压氧组相比,LDH释放量明显增多(P<0.05)。结论:HBO预处理通过调节自噬减轻缺血再灌注损伤,为HBO预处理神经保护提供一条新的作用机制。     

高压氧对脑缺血再灌注海马CA_1区神经元凋亡作用的研究

目的和方法 :应用TUNEL检测技术 ,对沙土鼠前脑缺血 2 0min后再灌注 3d模型 ,用HBO治疗连续 3d。观察HBO作用下海马CA1区神经元凋亡变化 ,研讨HBO对脑缺血再灌注损伤的疗效及其机理 ,为临床应用HBO治疗疾病提供理论依据。结果 :沙土鼠脑缺血再灌注 3d后海马CA1区大量神经元凋亡 ,HBO治疗组凋亡细胞数明显减少 (P <0 .0 1) ,并以 0 .2 5MPaHBO治疗组为佳。结论 :HBO治疗对海马神经元损伤有保护作用 ,减少神经元凋亡 ,为高压氧治疗缺血性损伤的疗效机理之一     

邻苯二甲酸二丁酯(DBP)对大鼠认知功能的影响

目的:观察邻苯二甲酸二丁酯(DBP)对大鼠认知功能的影响.方法:15月成熟雄性Wistar大鼠40只,随机分为4组(n=10)、对照组(C组)、DBP暴露组(E组)、药物预防组(P组)、药物治疗组(T组).E组食用经DBP浸泡后的食物3个月、P组食用经DBP浸泡后的食物3个月,期间每天注射抗小胶质细胞活化药物吲哚美辛(按照2.5mg/kg,2次/天,腹腔注射),T组食用经DBP浸泡后的食物3个月后使用吲哚美辛治疗(按照2.5mg/kg,2次/天,腹腔注射1周),N组给予同剂量的生理盐水腹腔注射.各组于停药后1d使用Morris水迷宫实验,末次水迷宫测试结束后1h处死大鼠,取海马组织进行化学比色法检测其海马组织内AChE活性.结果:E、P、T组与对照组组比较,大鼠学习记忆能力均明显降低(P＜0.001),AChE活性明显增加(P＜0.001);P、T组与E组,P组与T组相比,大鼠学习能力及记忆能力无显著性差异(P＞0.05),AChE活性无显著性变化(P＞0.05).结论:DBP可引起正常大鼠认知功能障碍,其机制可能与大鼠海马组织AChE活性增加有关.     

海马齿状回神经再生对WKY大鼠抑郁样行为的影响*

目的:观察海马齿状回(DG)神经再生对成年Wistar Kyoto(WKY)大鼠抑郁样行为的影响。方法:实验共分三个组(n = 10):①正常对照(Wistar)组:选取 9 周龄Wistar大鼠,给予生理盐水 3 周(10 mg/kg, 灌胃);②抑郁模型(WKY)组:选取同龄WKY大鼠并经行为学测定后筛选出抑郁大鼠作为抑郁模型组,给予生理盐水 3 周(10 mg/kg, 灌胃);③阳性对照(AMI+WKY)组:选取同龄WKY抑郁大鼠,给予阿米替林(AMI) 3 周(10 mg/kg, 灌胃)。选用免疫荧光染色细胞增殖标记物Ki67、未成熟神经元标志物DCX检测大鼠的海马神经再生水平;应用糖水偏好实验(SPT)、旷场实验(OFT)和强迫游泳实验(FST)检测各组大鼠的抑郁样行为学变化。结果:①WKY抑郁大鼠海马DG区细胞增殖标志物Ki67⁺细胞数和未成熟神经元标志物DCX⁺细胞数较Wistar大鼠分别降低了 33.0%(P＜0.01)和39.2%(P＜0.01);阿米替林给药后使抑郁大鼠海马DG区Ki67⁺细胞数和DCX⁺细胞数分别增加了43.8%(P＜0.01)和46.7%(P＜0.01)。②与Wistar大鼠相比,WKY抑郁大鼠糖水偏好程度明显降低(P＜ 0.01),旷场实验中运动总距离显著缩短(P＜0.01)和中心停留时间显著减少(P＜0.01),强迫游泳实验中不动时间明显延长(P＜ 0.01);阿米替林治疗可显著改善WKY大鼠的上述抑郁样行为。结论:①成年WKY抑郁大鼠的海马神经干细胞的增殖和分化能力较正常对照组显著降低,提示成年WKY抑郁大鼠的神经再生受损;②改善海马受损的神经再生可以部分逆转成年WKY大鼠的抑郁样行为。     

氟西汀抑制PTSD大鼠海马神经元PSD-95和突触素Ⅰ水平的下调与学习记忆力的损害

目的探讨氟西汀(fluoxetine,FLXT)对创伤后应激障碍(post-traumatic-stress-disorder,PTSD)大鼠记忆及大鼠海马神经元突触后致密物蛋白95(postsynaptic density 95,PSD-95)和突触素Ⅰ(synapsinⅠ)表达的影响。方法采用国际认定的SPS方法刺激大鼠建立PTSD大鼠模型,应用水迷宫实验观察氟西汀对PTSD大鼠学习记忆的影响,采用免疫荧光染色和免疫印迹法检测海马神经元PSD-95和突触素Ⅰ水平。结果 Morris水迷宫前5天的定位航行实验结果显示,SPS刺激后大鼠(PTSD大鼠)找到水下平台的游泳距离和潜伏期比正常组大鼠长,给予氟西汀的PTSD大鼠找到水下平台的距离和潜伏期较未用氟西汀处理的PTSD大鼠缩短。Morris水迷宫第6天空间探索实验结果显示,PTSD大鼠穿越平台的次数和在靶象限花费时间的百分比明显低于正常对照大鼠,而氟西汀可显著增加PTSD大鼠在水迷宫实验中的穿台次数和在靶象限停留的时间百分比。免疫荧光染色和Western Blot检测显示,PTSD大鼠PSD-95和突触素Ⅰ的水平降低,氟西汀干预可抑制PTSD大鼠PSD-95和突触素Ⅰ水平的降低。结论氟西汀可通过抑制PTSD大鼠海马神经元细胞PSD-95和SynapsinⅠ水平的下调,减轻PTSD大鼠空间记忆和学习能力的损伤。     

早期游泳运动对慢性温和应激抑郁大鼠学习和记忆能力的影响

目的:探讨早期游泳运动对慢性温和应激(chronic mild stress,CMS)大鼠学习和记忆能力的影响。方法:50只SD大鼠随机分成5组:对照组、模型组、低强度运动组、中等强度运动组、高强度运动组。运动组大鼠按照游泳运动方案运动4 w,糖水消耗实验和强迫游泳实验评价大鼠抑郁程度;Morris水迷宫实验评价大鼠学习记忆能力。结果:模型组大鼠糖水消耗量和游泳不动时间较对照组明显降低(P0.01),低强度运动组和中等强度运动组大鼠较模型组糖水消耗量和游泳不动时间明显增加(P0.05或P0.01);模型组大鼠较对照组逃避潜伏期明显延长,目标象限搜索时间占总游泳时间的百分比和目标象限穿过次数减少,体质量、双侧海马质量和海马相对质量下降(P0.05或P0.01);低强度运动组和中等强度运动组大鼠较模型组比较,潜伏期缩短明显,目标象限搜索时间占总游泳时间的百分比和目标象限穿过次数增加,体质量、双侧海马质量和海马相对质量增加(P0.05或P0.01)。结论:早期游泳运动能减轻慢性温和应激抑郁大鼠的学习记忆的损害,其中低强度和中等强度运动训练作用效果最佳。     

KA海马注射对大鼠学习和记忆的影响及雷公藤甲素的保护作用

目的:观察海人藻酸(Kainic acid,KA)海马内注射后大鼠学习记忆的变化及雷公藤甲素(TRP)对其的影响.方法:采用Morris水迷宫筛选空间学习记忆能力正常的SD雄性大鼠90只(200-220g).将实验动物分为:右侧海马注射生理盐水后生理盐水灌胃对照组(NS+NS)、右侧海马注射海人藻酸后生理盐水灌胃干预组(KA+NS)、右侧海马注射海人藻酸后雷公藤甲素灌胃干预组(KA+TRP).动物分别存活1天、3天、5天、7天、14天,用Morris水迷宫检测各组动物空间位置记忆能力:尼氏染色法观察海马CA1区神经元数目和形态.结果:与NS组(NS+NS)比较,KA组(KA+NS)大鼠逃避潜伏期延长(P<0.05).跨越原平台次数减少(P<0.05);CA1区的神经元出现胞体肿胀、排列散乱等形态改变及神经元的丢失(P<0.05);TRP组(TRP+KA)与KA组比较,大鼠的平均逃避潜伏期从第5天起缩短(P＜0.05),跨越原平台次数增多(P<0.05),神经元形态好转,数目增多.结论:KA 海马内注射,可以导致大鼠学习记忆功能障碍及神经元形态的改变;雷公藤甲素干预治疗,能够改善动物的学习和记忆能力,保护海马神经元.     

Hyperbaric Oxygen Preconditioning Protects Against Cerebral Ischemia/Reperfusion Injury by Inhibiting Mitochondrial Apoptosis and Energy Metabolism Disturbance

Hyperbaric oxygen (HBO) therapy is considered a safe and feasible method that to provide neuroprotection against ischemic stroke. However, the therapy mechanisms of HBO have not been fully elucidated. We hypothesized that the mechanism underlying the protective effect of HBO preconditioning (HBO-PC) against cerebral ischemia/reperfusion injury was related to inhibition of mitochondrial apoptosis and energy metabolism disorder. To test this hypothesis, an ischemic stroke model was established by middle cerebral artery occlusion (MCAO) in rats. HBO-PC involved five consecutive days of pretreatment before MCAO. In additional experiments, X chromosome-linked inhibitor of apoptosis protein (XIAP) and second mitochondria-derived activator of caspases (SMAC) shRNA and NC plasmids were intraventricularly injected into rat brains after MCAO (2 h). After 24 h, all rats underwent motor function evaluation, which was assessed by modified Garcia scores. TTC staining for the cerebral infarct and cerebral edema, and TUNEL staining for cell apoptosis, were also analyzed. Reactive oxygen species and antioxidative enzymes in rat brains were detected, as well as mitochondrial complex enzyme activities, ATP levels, and Na⁺/K⁺ ATPase activity. Western blot was used to detect apoptotic proteins including Bcl-2, Bax, caspase-3, caspase-9, cyc-c, XIAP, and SMAC. HBO-PC remarkably reduced the infarct volume and improved neurological deficits. Furthermore, HBO-PC alleviated oxidative stress and regulated the expression of apoptosis-related proteins. Moreover, HBO-PC inhibited the decrease in ATP levels, mitochondrial complex enzyme activities, and Na⁺/K⁺ ATPase activity to maintain stable energy metabolism. XIAP knockdown weakened the protective effect of HBO, whereas SMAC knockdown strengthened its protective effect. The effects of HBO-PC can be attributed to inhibition of ischemia/hypoxia-induced mitochondrial apoptosis and energy metabolism disturbance. The action of HBO-PC is related to the XIAP and SMAC signaling pathways.

     

高压氧预处理对减压病脑组织MMP-9表达与相关元素关系研究

目的:探讨高压氧预处理对减压病大鼠脑组织基质金属蛋白酶-9(matrix metalloproteinases-9,MMP-9)蛋白的表达与相关金属元素的关系。方法:雄性SD大鼠36只,随机分为正常对照组(NC group)、减压组(DCS group)、HBO预处理组(HBO-PC group),每组12只。连续进行高压氧(hyperbaric oxygen,HBO)预处理5天后建立减压病模型,原子吸收分光光度计测定各组大鼠脑组织元素锰、锌、铁和镁的含量;免疫组织化学法测定MMP-9蛋白表达,并对两者的结果做相关性分析。结果:减压组镁、锌、铁的含量降低,高压氧预处理组锌、镁含量降低而锰、铁的含量升高(P0.05);与减压组相比,高压氧预处理组锰、锌、铁、镁含量均升高(P0.05);减压组中MMP-9表达较对照组明显增加(P0.05),高压氧预处理组MMP-9表达被抑制,与减压组相比明显减少(P0.05);脑组织MMP-9阳性细胞表达数与相关的金属元素锌、镁含量呈负相关(P0.05)。结论:金属元素锌、镁的含量与MMP-9的表达在减压病发生过程中起着非常重要的作用,高压氧预处理可以通过调节元素锌与镁的含量与MMP-9的表达来抑制减压病发生时的大鼠脑组织的氧化损伤,从而起到对减压病的保护作用。     

Hyperbaric Oxygen Preconditioning Induces Tolerance against Oxidative Injury and Oxygen-Glucose Deprivation by Up-Regulating Heat Shock Protein 32 in Rat Spinal Neurons

Objective

Hyperbaric oxygen (HBO) preconditioning (HBO-PC) has been testified to have protective effects on spinal cord injury (SCI). However, the mechanisms remain enigmatic. The present study aimed to explore the effects of HBO-PC on primary rat spinal neurons against oxidative injury and oxygen-glucose deprivation (OGD) and the relationship with heat shock proteins (HSPs).

Methods

Primary rat spinal neurons after 7 days of culture were used in this study. HSPs were detected in rat spinal neurons following a single exposure to HBO at different time points by Western blot. Using lactate dehydrogenase release assay and cell counting kit-8 assay, the injuries induced by hydrogen peroxide (H2O2) insult or OGD were determined and compared among neurons treated with HBO-PC with or without HSP inhibitors.

Results

The results of Western blot showed that HSP27, HSP70 and HSP90 have a slight but not significant increase in primary neurons following HBO exposure. However, HSP32 expression significantly increased and reached highest at 12 h following HBO exposure. HBO-PC significantly increased the cell viability and decreased the medium lactate dehydrogenase content in cultures treated with H2O2 or OGD. Pretreatment with zinc protoporphyrin IX, a specific inhibitor of HSP32, significantly blocked the protective effects of HBO-PC.

Conclusions

These results suggest that HBO-PC could protect rat spinal neurons in vitro against oxidative injury and OGD mostly by up-regulating of HSP32 expression.     

The apoptosis of peripheral blood lymphocytes promoted by hyperbaric oxygen treatment contributes to attenuate the severity of early stage acute pancreatitis in rats

The aim of this study was to investigate the immunoregulatory effects of hyperbaric oxygen (HBO) via promoting the apoptosis of peripheral blood lymphocytes (PBLs) to attenuate the severity of early stage acute pancreatitis (AP) in rats. Additionally, the persistence of the HBO treatment effects was evaluated. One hundred and twenty male Wistar rats were randomized into four groups: sham, AP, AP + normobaric oxygen (NBO), and AP + HBO. Each group consisted of 30 rats. Four hours after the induction of AP, the 30 rats in the AP + NBO group were given normobaric oxygen treatment with 100 % oxygen at 1 atm for 90 min. The 30 rats in the AP + HBO group received 100 % oxygen at 2.5 atm for 90 min, with a compression/decompression time of 15 min. The 30 rats in the AP group remained untreated. At 6, 12, and 24 h after the induction of AP, surviving rats from each group were sacrificed, and the blood and tissue samples were collected for the following measurements: the partial pressure of oxygen (PaO₂) and oxygen saturation (SaO₂) of the arterial blood, the levels of serum amylase, lipase, interleukin-2 (IL-2), interferon-γ (IFN-γ), interleukin-10 (IL-10), hepatocyte growth factor (HGF), and reactive oxygen species (ROS), and the mitochondrial membrane potential (?Ψm) of the PBLs. The expression levels of procaspase-3, caspase-3, procaspase-9, and caspase-9 were also evaluated in the PBLs. Additionally, the apoptosis of PBLs was assessed, and the pancreatic tissues were subjected to a histopathological analysis by pathological grading and scoring. The histopathology of the lung, liver, kidney, duodenum, and heart was also analyzed at 12 h after the induction of AP. Significant differences were found at 6 and 12 h after AP induction. The HBO treatment significantly elevated the PaO₂ and SaO₂ levels, and the ROS levels in the PBLs. Additionally, HBO downregulated the levels of amylase and lipase. The HBO treatment also reduced the ?Ψm levels, upregulated the expression of caspase-3 and caspase-9, and increased the apoptosis rate of the PBLs. Moreover, the HBO treatment decreased the serum concentrations of IL-2, IFN-γ and HGF, and reduced the pathological scores of the pancreatic tissue. The histopathological changes of the lung, liver, kidney, duodenum, and heart were also improved. A significant elevation of IL-10 occurred only at the 12-h time point. However, no obvious differences were found at the 24-h time point. This study demonstrated that the HBO treatment can promote the apoptosis of PBLs via a mitochondrial-dependent pathway and inhibit the inflammatory response. These immunoregulatory effects may play an important therapeutic role in attenuating the severity of early stage AP. The repeated administration of HBO or the use of HBO in combination with other approaches may further improve outcomes.     

常压氧与高压氧对成年大鼠脑缺血再灌注损伤后 微血管新生影响的比较

目的:研究常压氧与高压氧对成年大鼠脑缺血再灌注损伤后微血管新生影响的差异。方法:将成年SD雄性大鼠随机分为三组:假手术组(SS组)、常压氧治疗组(NBO组)、高压氧治疗组(HBO组),每组又随机分为3、7、10天三个亚组。采用线栓法对NBO组和HBO组大鼠进行大脑中动脉栓塞(MCAO),缺血1.5小时后拔出栓子再灌注,NBO组进行常压氧治疗,HBO组进行高压氧治疗。大鼠分别在3、7、10天麻醉处死,取脑组织切片,血管内皮生长因子(VEGF)、VEGF受体-1(FLT-1)和CD34免疫组化染色,光镜观察取图和统计分析。结果:NBO各组与SS各组相比,VEGF、FLT-1和CD34阳性细胞数目均明显增多(P<0.05);HBO各组与NBO各组比较,7天、10天组VEGF、FLT-1和CD34阳性细胞数目均显著增多(P<0.05)。结论:HBO治疗较NBO治疗对成年大鼠微血管的新生更有促进作用。     

Hyperbaric oxygen preconditioning promotes angiogenesis in rat liver after partial hepatectomy

Hyperbaric oxygen preconditioning (HBO-PC) increases the level of HIF-1alpha (hypoxia inducible factor-1alpha) and its target gene VEGF (vascular endothelial growth factor) which is involved in angiogenesis. Liver regeneration is an angiogenesis-dependent process. We hypothesized that HIF-1alpha and VEGF mediated the angiogenesis effect of HBO-PC on regenerating rat liver. Male Sprague Dawley rats received HBO-PC followed by 70% partial hepatectomy. Proliferation of hepatocytes and endothelial cells was evaluated by BrdU (bromodeoxyuridine) staining. Microvascular density was assessed by immunohistochemistry. mRNA expression of HIF-1alpha was assessed by quantitative RT-PCR and protein levels of HIF-1alpha and VEGF were assessed by western blot. HIF-1alpha DNA-binding activity was determined with an ELISA-based kit. HBO-PC increased the proliferation index of endothelial cells and microvascular density at 48 h after partial hepatectomy. The protein level and DNA-binding activity of HIF-1alpha and the protein level of VEGF were increased by HBO-PC before and after partial hepatectomy. Partial hepatectomy alone also increased proliferation index and the expressions of HIF-1alpha and VEGF. Our results indicated that the angiogenesis effect of HBO-PC on liver after partial hepatectomy could be achieved by increased HIF-1alpha activity and VEGF expression. However, the angiogenic effect of HBO-PC is moderate and HBO-PC failed to produce additional effect on the enhancement of HIF-1alpha and VEGF induced by partial hepatectomy alone.     

高压氧治疗创伤性脑损伤的效用及机制研究

目的:研究高压氧(HBO)对大鼠创伤性脑损伤(TBI)治疗效用并观察脑组织星形胶质细胞活化及胶质细胞源性神经营养因子(GDNF)和神经生长因子(NGF)表达的变化以探讨作用机制。方法:SD雄性大鼠54只,随机分为3组(n=18):假手术组、TBI组和HBO治疗组。采用Feeney法建立大鼠TBI模型,假手术组只开放骨窗,不予打击。HBO治疗组大鼠于脑损伤后6 h采用动物高压舱,以3ATA压力纯氧治疗60 min。TBI后48 h测量神经功能,然后分离脑组织,其中18只用干湿法测定脑含水量;18只脑组织用于切片,部分进行尼氏染色后作形态学观察,部分进行免疫组织化学染色,检测星形胶质细胞标记物胶质纤维酸性蛋白(GFAP)、波形蛋白(vimentin)与S100蛋白的表达;另18只大鼠取伤侧脑半球,进行Western blot分析,观察GDNF和NGF的表达。结果:HBO治疗能减轻神经功能障碍,降低脑含水量,减少海马部位神经细胞丢失,进一步激活损伤侧皮质与海马部位GFAP、vimentin与S-100阳性表达星形胶质细胞,促进损伤侧脑组织GDNF与NGF的表达。结论:HBO对创伤性脑损伤有较好治疗效果,其机制与上调GDNF和NGF的表达有关。     

The influence of hyperbaric oxygen on hemorheological parameters in diabetic rats

The effect of hyperbaric oxygen (HBO2) treatment on hemorheological parameters of diabetic rats was investigated. This study is a placebo-controlled, in vivo animal study. 30 streptozocin-induced diabetic rats were divided into two groups; one group received hyperbaric oxygen treatment while the other did not. Hematological and hemorheological parameters were tested with blood samples collected directly from the heart using surgical procedures. Student t-tests with a type I (alpha) error at 0.05 was used to test any significant difference between means of the hematologic and hemorheological parameters of the control (CON) and the HBO2 groups. Compared with the placebo group, hyperbaric oxygen resulted in significant higher lipid peroxidation stress of the erythrocytes and resistance of erythrocytes to deformation in rats of the HBO2 group. Whole blood viscosities measured at shear rates of 5, 150 and 400 s(-1) were all higher for the rats in the HBO2 group than those for rats in the control group. In addition, the oxygen delivery index was found to be significantly lower in rats of the HBO2 group. Thus, our work demonstrates that hyperbaric oxygen treatment significantly changes the hemorheological parameters in diabetic rats.     

Preventive effects of hyperbaric oxygen treatment on glycerol-induced myoglobinuric acute renal failure in rats

Myoglobinuric acute renal failure (ARF) is a uremic syndrome caused by traumatic or non-traumatic skeletal muscle breakdown and intracellular elements that are released into the bloodstream. We hypothesized that hyperbaric oxygen (HBO) therapy could be beneficial in the treatment of myoglobinuric ARF caused by rhabdomyolysis. A total of 32 rats were used in the study. The rats were divided into four groups: control, control+hyperbaric oxygen (control+HBO), ARF, and ARF+hyperbaric oxygen (ARF+HBO). Glycerol (8 ml/kg) was injected into the hind legs of each of the rats in ARF and ARF+HBO groups. 2.5 atmospheric absolute HBO was applied to the rats in the control+HBO and ARF+HBO groups for 90 min on two consecutive days. Plasma urea, creatinine, sodium, potassium, calcium, aspartate aminotransferase, alanine aminotransferase, lactic dehydrogenase, creatinine kinase and urine creatinine and sodium were examined. Creatinine clearance and fractional sodium excretion could then be calculated. Superoxide dismutase, catalase, glutathione and malondialdehyde (MDA) levels were assessed in renal tissue. Tissue samples were evaluated by Hematoxylin-eosin, PCNA and TUNEL staining histopathologically. MDA levels were found to be significantly decreased whereas SOD and CAT were twofold higher in the ARF+HBO group compared to the ARF group. Renal function tests were ameliorated by HBO therapy. Semiquantitative evaluation of histopathological findings indicated that necrosis and cast formation was decreased by HBO therapy and TUNEL staining showed that apoptosis was inhibited. PCNA staining showed that HBO therapy did not increase regeneration. Ultimately, we conclude that, in accordance with our hypothesis, HBO could be beneficial in the treatment of myoglobinuric ARF.