促红细胞生成素对脊髓缺血再灌注损伤保护作用及其机理的实验研究

目的:探讨促红细胞生成素(EPO)处理对脊髓缺血再灌注损伤的保护作用及其可能的作用机理.方法:建立兔脊髓缺血再灌注损伤模型,通过动物神经运动功能评分和组织学染色评价神经损伤程度;采用免疫组织化学染色测量bcl-2和bax蛋白表达情况;TUNEL法检测脊髓细胞凋亡情况.结果:EPO处理组能明显改善动物的神经运动功能并减轻脊髓由于缺血再灌注所引起的病理性损害:EPO组与对照组相比,脊髓前角细胞的凋亡指数明显下降(P＜0.05),脊髓内bcl-2表达增高(P＜0.01),而bax蛋白表达下降(P＜0.01).结论:EPO对脊髓由于缺血而引起的神经运动功能损害具有保护作用,此种保护作用与EPO能够上调bcl-2和下调bax蛋白表达有关.     

促红细胞生成素与肾缺血再灌注损伤

缺血再灌注损伤(IRI)在肾移植过程中是不可避免的,近来研究发现促红细胞生成素(EPO)能显著减轻肾脏的IRI,保护肾脏的结构和功能。本文综述了EPO在肾脏缺血再灌注损伤中的作用及可能机制。     

促红细胞生成素与肾缺血再灌注损伤

缺血再灌注损伤(IRI)在肾移植过程中是不可避免的，近来研究发现促红细胞生成素(EPO)能显著减轻肾脏的IRI，保护肾脏的结构和功能。本文综述了EPO在肾脏缺血再灌注损伤中的作用及可能机制。     

促红细胞生成素对大鼠移植肾缺血-再灌注损伤的防护作用

探讨促红细胞生成素(erythropoietin,EPO)对大鼠移植肾缺血-再灌注损伤(ischemia-reperfusion injury,IRI)的保护作用.方法 采用BN大鼠和Lewis大鼠,分别随机分为实验组和对照组,每组各15只.BN大鼠作为供体,Lewis大鼠为受体,建立单侧原位大鼠肾移植模型.实验组受体大鼠术后立即腹腔注射重组人促红细胞生成素(recombinant human erythropoietin,rhEPO)1 000 U/kg,对照组大鼠同样予腹腔注射等量生理盐水.两组受体大鼠在术后5d剪尾取血,检测血清肌酐(Scr)水平.同时将移植肾取出,肾组织行病理切片苏木素-伊红(HE)染色、过碘酸-雪夫(periodic acid Schiff,PAS)染色、马松(Masson)染色和过碘酸六胺银(periodic acid-silver methenamine,PASM)染色,观察肾组织病理学改变情况.结果 实验组受体大鼠术后Scr水平为(102±3)μmol/L,对照组为(369±7)μmol/L,两者比较差异有统计学意义(P<0.05).两组受体大鼠移植肾均出现肾小管坏死改变.对照组移植肾组织病理切片主要表现为大片肾组织坏死,提示出现严重的急性排斥反应、肾小管坏死及动脉损伤;实验组肾组织病理切片主要表现为肾被膜下小灶性肾组织凝固性坏死;与对照组相比,实验组肾组织坏死面积较小,提示急性排斥反应程度较轻.结论 肾移植术后早期使用EPO进行预处理可抑制肾脏IRI炎症反应,减少细胞凋亡,缓解移植后IRI.     

重组人促红细胞生成素预处理减轻大鼠肝脏缺血/再灌注损伤

目的探讨重组人促红细胞生成素(rhEPO)对大鼠肝脏缺血/再灌注损伤(IRI)的保护作用和机制。方法选取健康雄性Sprague-Dawley(SD)大鼠30只,随机均分为实验组(rhEPO组)、对照组及假手术组。rh EPO组术前1小时通过尾静脉注射5 000 U/kg的rhEPO,然后建立大鼠70%肝脏IRI模型。苏木素-伊红(HE)染色观察肝脏组织学变化;生化仪测定血清中天冬氨酸转氨酶(AST)和丙氨酸转氨酶(ALT)的释放量;蛋白免疫印迹试验(Western Blot)检测PI3K/AKT蛋白磷酸化水平;qPCR测定炎性细胞因子[肿瘤坏死因子(TNF-α)、白细胞介素(IL-6和IL-1β)] mRNA的表达;酶联免疫吸附试验(ELISA)测定血清中TNF-α、IL-6和IL-1β浓度。结果对照组有明显的肝组织损伤,血清中AST和ALT释放量均增加,而rhEPO组肝组织损伤程度较轻,转氨酶水平低于对照组[AST(U/L):582.0±52.5比245.0±31.7; ALT(U/L):388.0±39.6比166.0±24.3,均P <0.05]。蛋白检测发现rhEPO组p-p85和p-AKT的表达显著增加,明显高于对照组。qPCR提示rhEPO组炎性因子TNF-α、IL-6和IL-1βmRNA表达明显低于对照组。ELISA亦证实rhEPO组血清中TNF-α、IL-6和IL-1β分泌低于对照组[TNF-α(pg/ml):425.0±31.2比227.0±19.7;IL-6(pg/ml):353.0±26.4比189.0±16.3;IL-1β(pg/ml):511.0±39.6比328.0±23.2,均P <0.05]。结论 rhEPO预处理能抑制大鼠肝脏IRI时炎性因子释放,保护肝组织,其机制可能与PI3K/AKT信号的进一步活化有关。     

重组人促红细胞生成素对大鼠肾缺血再灌注损伤的保护作用

目的 探讨重组人促红细胞生成素(recombinant human erythropoietin,rhEPO)对大鼠急性肾缺血再灌注损伤(ischemia-reperfusion injury,IR/I)的保护作用及机制.方法 21只健康雄性S-D大鼠随机分为假手术组(sham组)、IR/I组和rhEPO预处理组.双侧肾蒂夹闭45min后再灌注,建立大鼠IR/I模型.术后24h收集血液和肾脏标本,观察肾功能、肾脏病理和大鼠死亡情况;ELISA法检测血清血管内皮生长因子(VEGF)的水平;免疫组织化学法观察肾脏血红素加氧酶-1(HO-1)的表达.结果 再灌注24h后,rhEPO预处理组Scr和BUN水平明显低于IR/I组(P＜0.01);IR/I组出现肾小管上皮细胞广泛性坏死,rhEPO预处理组肾脏病理损伤程度较IR/I组明显减轻(P＜0.01);IR/I组大鼠死亡率为28.6％(2/7),rhE-PO预处理组死亡率为0(0/7),Sham组死亡率为0(0/7).rhEPO预处理组血清VEGF水平明显升高、肾脏HO-1蛋白表达明显增加,均高于IR/I组及sham组(P＜0.01).结论 rhEPO对急性肾脏IR/I有较好的保护作用,该作用可能是通过抗氧化、促进肾小管上皮细胞再生等的协同机制来实现.     

急性脊髓损伤后促红细胞生成素受体的表达及其意义

目的探讨急性脊髓损伤后促红细胞生成素(EPO)及其受体(EPO-R)在脊髓内的表达。方法Wistar大鼠69只,随机分为三组：正常对照组(5只,不手术,作为后两组的对照)、假手术组(仅行椎板切除术)和脊髓损伤组。根据术后时间点不同后两组又分为1h、6h、12h、24h、3d、7d、14d和28d八个亚组(每组4只)。采用RT-PCR、Western blot免疫印迹法和免疫组织化学染色法检测EPO及EPO-R的表达。结果正常对照组、假手术组和脊髓损伤组在各时相点均未发现有EPO表达。正常对照组、假手术组未发现EPO-R的表达,脊髓损伤组在伤后1h未见EPO-R mRNA和蛋白的表达,6h开始有表达,12h有明显的表达,至24h达到高峰,3d和7d时仍维持在高表达水平,未见减弱,14d开始下降,至28d时仍有EPO-R蛋白的表达。免疫组化显示EPO-R阳性细胞主要位于神经元、少突胶质细胞、血管内皮细胞和脊髓中央管内室管膜细胞。结论大鼠急性脊髓损伤后脊髓内大量表达EPO-R,这是外源性EPO与EPO-R结合产生神经保护作用的分子基础。     

重组人促红细胞生成素对骨骼肌缺血再灌注损伤的保护作用

[目的]观察重组人促红细胞生成素（rHuEPO）对肢体骨骼肌缺血再灌注（IZR）损伤的保护作用。[方法]建立大鼠后肢缺血再灌注模型。40只大鼠随机均分为：假手术组（I组），I/R组（Ⅱ组），I/R＋生理盐水组（Ⅲ组），I/R＋rHuEPO组（Ⅳ组）。取血浆测定丙二醛（MDA）、肌酸磷酸激酶（CPK）和乳酸脱氢酶（LDH）含量。取骨骼肌标本测定髓过氧化酶（MP0）活性、湿重／干重比（Wet／dry）。[结果]Ⅱ组与I组比较，血浆和骨骼肌的各项生化指标显著增高（P〈0．01）；IV组血浆及骨骼肌各项测定指标较Ⅱ组相比明显降低（P〈0．01）。Ⅲ组和Ⅱ组之间比较，差异无显著意义。[结论]rHuEPO对肢体骨骼肌缺血再灌注损伤有保护作用。     

促红细胞生成素对缺血/再灌注心肌保护作用的研究进展

背景 促红细胞生成素(erythropoietin,EPO)是一种造血刺激因子,过去20多年中用于临床多种原因所致的贫血.随着对EPO及其受体在心血管方面作用的认识,增加了EPO在生理和病理生理方面作用的理解. 目的 将心肌缺血/再灌注损伤(ischemia/reperfusion injury,I/RI)减轻到最低限度. 内容 研究EPO在心脏中的表达及其在心肌保护中所涉及的传导机制,EPO在动物心血管疾病实验模型中起到心肌保护作用及目前EPO心肌保护作用的临床相关研究. 趋向 近年来,EPO心肌保护作用临床研究的报道逐渐增多,为临床心肌保护提供了新的方向,但需要更深入研究EPO的心肌保护作用.     

重复高压氧预处理对大鼠脊髓缺血再灌注时低氧诱导因子-1α及促红细胞生成素表达的影响

目的 探讨重复高压氧预处理对大鼠脊髓缺血再灌注时低氧诱导因子-1α(HIF-1α)和促红细胞生成素(EPO)表达的影响.方法 雄性SD大鼠48只,体重250～300g,采用随机数字表法,将其随机分为3组(n=16):假手术组(S组)、脊髓缺血再灌注组(I/R组)和重复高压氧预处理(HOP组).HOP组实施高压氧预处理,参数为:氧浓度＞98%,氧含量1000ml/L,压力2.5 ATA,1 h/d,连续5 d,最后1 d处理后24 h,I/R组和HOP组采用夹闭腹主动脉20min再开放的方法制备脊髓缺血再灌注模型.再灌注48h时评价后肢运动功能,然后处死大鼠,取L5-7节段脊髓组织,测定HIF-1α、EPO的mRNA及其蛋白表达水平,光镜下观察病理学结果.结果 与S组比较,I/R组和HOP组后肢运动功能和脊髓前角正常运动神经元计数降低,脊髓组织HIF-1α、EPO的mRNA及其蛋白表达水平上调(P＜0.05);与I/R组比较,HOP组后肢运动功能和脊髓前角正常运动神经元计数升高,脊髓组织HIF-1α及EPO的mRNA及其蛋白表达水平上调(P＜0.05).HOP组脊髓组织病理学损伤程度轻于I/R 组.结论 重复高压氧预处理可上调HIF-1α及EPO表达,从而减轻大鼠脊髓缺血再灌注损伤.

Abstract：

Objective To investigate the effect of repeated hyperbaric oxygen preconditioning (HOP) on the expression of hypoxia-inducible factor-1 alpha (HIF-1a) and erythropoietin (EPO) following spinal ischemiareperfusion (I/R) in rats. Methods Forty-eight male SD rats weighing 250-300 g were randomly divided into 3 groups (n = 16 each): sham operation group (S group); I/R group and repeated HOP group (HOP group). The animals in HOP group were pretreated with O2 ( ＞ 98 % ) at 2.5 ATA I h/d for 5 consecutive days at 24 h before spinal cord I/R. The animals were anesthetized with intraperitoneal pentobarbital sodium 35 mg/kg. Spinal cord ischemia was produced by cross-clamping of abdominal aorta distal to renal artery for 20 min in I/R and HOP groups. Hind-limb motor function was assessed and scored st 48 h of reperfusion. The animals were then sacrificed and the L5-7 segment of the spinal cord was removed for determination of the expression of HIF-1 α and EPO mRNA and protein and microscopic examination. Results Compared with group S, the hind-limb motor function scores and the number of normal motor neurons in the anterior horn of the spinal cord were significantly decreased, and the expression of HIF-1α and EPO mRNA and protein was up-regulated in I/R and HOP groups ( P ＜ 0.05). Compared with group I/R, the hind-limb motor function scores and the number of normal motor neurons in the anterior horn of the spinal cord were significantly increased, and the expression of HIF-1α and EPO mRNA and protein was up-regulated in group HOP ( P ＜ 0.05). The spinal cord injury was attenuated in group HOP compared with group I/R. Conclusion Repeated HOP can reduce the spinal cord I/R injury though up-regulating the expression of HIF1α and EPO in rats.     

促红细胞生成素治疗急性脊髓损伤

目的 观察促红细胞生成素(EPO)对急性脊髓损伤神经功能恢复的疗效.方法 急性脊髓损伤患者65例,根据用药分为EPO治疗组35例和对照组30例;分别于入院时及治疗后末次随访时对脊髓损伤程度按ASIA2000评分标准进行神经功能评定,观察两组差异;同时监测患者用药前后血常规及血清EPO浓度,记录不良反应.结果 65例患者术后随访1～3年,平均1.7年,末次随访时治疗组患者ASIA运动、触觉、痛觉功能评分为58,2±8.2、78.5±11.5、82.6±13.5,显著优于对照组运动、触觉、痛觉功能评分45.6±6.8、65.5±13.4、68.7±14.7,差异有统计学意义(P<0.05),EPO组治疗过程中未见明显不良反应.结论 促红细胞生成素是治疗急性脊髓损伤安全有效的药物,早期应用EPO对促进患者神经功能的改善与恢复具有积极意义.     

脊髓损伤后促红细胞生成素对bcl-2的影响

目的 探讨促红细胞生成素（EPO）对大鼠脊髓损伤后伤区脊髓细胞凋亡和神经功能恢复的影响。方法 Wistar大鼠210只，随机分为4组：假手术组、脊髓损伤组、脊髓损伤加重组人EPO治疗组、脊髓损伤加生理盐水治疗组。采用原位末端脱氧核糖核苷酸转移酶介导dUTP标记（TUNEL标记法）检测神经元和少突胶质细胞凋亡，Western blot免疫印迹法和免疫组化染色检测bcl-2表达，免疫组化染色和图像分析方法观察对白质内神经纤维（NF-200染色）的保护作用，通过感觉诱发电位（SSEP）、运动诱发电位（MEP）和大鼠BBB后肢运动功能评分，观察损伤脊髓传导功能的恢复。结果 EPO保护组bcl-2在各时相点的表达明显增高，8h和7d时神经元和少突胶质细胞的TUNEL阳性细胞数明显减少；在7d时白质中NF-200阳性神经纤维明显增多；SSEP和MEP的平均潜伏期和波幅以及BBB功能评分明显提高，与损伤组和生理盐水治疗相比，差异有统计学意义（P〈0．01）。结论 EPO通过上调bcl-2的表达，在抑制脊髓损伤后神经元和少突胶质细胞的凋亡中起到神经保护作用。     

The effects of systemically administered methylprednisolone and recombinant human erythropoietin after acute spinal cord compressive injury in rats

The study design was to decrease the damage of spinal cord on the experimentally induced acute spinal cord injury in rats. The objective of this study was to evaluate whether recombinant human erythropoietin (rHu-EPO) and methylprednisolone (MPSS) improve neurological function and histopathological changes if systemically administered after traumatic spinal cord injury. This study included 48 rats that underwent experimental SCI. Forty-eight animals were randomly divided into six groups. Animals constituted a moderate compression of 0.6 N that was produced by application of an aneurysm clip at level T3 for 1 min. rHu-EPO (1,000 and 3,000 U (Unit) per kg of body weight i.p.) and MPSS (30 mg/kg) were administered 5 min after injury, and control group was saline treated. (1) Control group (n=8), (2) MPSS group (n=8), (3) rHu-EPO 1,000 U group (n=8), (4) MPSS + rHu-EPO 1,000 U group (n=8), (5) rHu-EPO 3,000 U group (n=8), and (6) MPSS + rHu-EPO 3,000 U group (n=8). The neurological function and histopathology were evaluated at 24 and 72 h. According to the neurological functional test scores significant improvements between the control group and the other groups that had taken medical treatment were observed (P<0.001). Histopathologically severe ischemic findings were observed in the control group. A significant decrease in ischemic damage was detected in MPSS + rHu-EPO 3,000 U group (P<0.001). The most significant neurological functional and histopathological improvements were observed after systemical administration of MPSS + rHu-EPO 3,000 U and rHu-EPO 3,000 U. Furthermore, the MPSS + rHu-EPO 3,000 U group provides the most improved neurological functional and histopathological recovery.     

缺血后处理对兔脊髓缺血-再灌注损伤的保护作用

目的研究缺血后处理是否可以减轻兔脊髓缺血再灌注的损伤。方法雄性新西兰大白兔30只,随机分为五组,每组6只。假手术组(N1组)仅行单纯手术操作但不阻闭腹主动脉;对照组(N2组)行单纯缺血再灌注;缺血后处理15s/30s/60s(PA/PB/PC组)分别于阻闭腹主动脉15min后,再灌注15s/30s/60s,缺血15s/30s/60s,反复3次。再灌注48h时对所有动物的后肢运动功能进行评分并行脊髓前角正常神经元计数。结果PB组再灌注48h后肢运动功能评分[3.5(2～4)分],明显高于N2组[2(1～3)分](P<0.05),其他各组与N2组相比差异无显著意义。脊髓前角正常神经元计数PB组为36.7±7.0,明显多于N2组25.7±4.3(P<0.01),而PA组18.2±2.2和PC组8.0±4.1则明显少于N2组(P<0.05)。结论缺血后处理对兔脊髓缺血再灌注损伤的作用取决于后处理时间,缺血后处理30s/30s对脊髓缺血再灌注损伤具有保护作用,而缺血后处理15s/15s和60s/60s会加重脊髓损伤。     

The comparison of recovery patterns between ischemic spinal cord injury and traumatic spinal cord injury from acute to chronic phase

Objective: To investigate the neurological and functional recovery patterns of ischemic spinal cord injury (ISCI) compared with traumatic spinal cord injury (TSCI) in the acute to chronic phase.Design: Retrospective cohort study.Settings: Department of Neurology, Neurosurgery, Rehabilitation Medicine at a tertiary hospital.Participants: Fifty-four patients with ISCI and 86 patients with TSCI.Interventions: Not applicable.Outcome measures: MRI findings, American Spinal Injury Association Impairment Scale (AIS), modified Rankin Scale (mRS), Korean Spinal Cord Independence Measure (KSCIM), ambulatory status, and bladder status were reviewed. The functional outcomes were measured at admission, discharge, and >6 months after discharge.Results: AIS classification did not significantly change after 6 months in both ISCI and TSCI groups. Between admission and discharge, the proportion of patients needing a wheelchair or assistive device to ambulate decreased more in the ISCI group compared with the TSCI group [odds ratio (OR) 0.40, P = 0.04]. In addition, the proportion of catheterized voiding in the ISCI group was significantly higher than in the TSCI group at all time points (OR 5.12, P < 0.001). Lastly, both groups showed that functional improvement was the greatest between admission and discharge. In addition, the proportion of catheterized voiding decreased (Diff = −0.12, P = 0.019) and mRS score decreased (Diff=−0.48, P < 0.001) significantly in the ISCI group at >6 months post discharge.Conclusion: The ISCI group showed better recovery of mobility during inpatient rehabilitation period and worse recovery of bladder function as demonstrated by higher number of patients requiring bladder catheterization at all time points when compared with the TSCI group.     

促红细胞生成素和羊膜间充质干细胞协同治疗促进脊髓损伤再生

目的 观察促红细胞生成素和羊膜间充质干细胞对脊髓损伤(SCI)的综合治疗效应.方法 60只SD大鼠在T11水平进行脊髓半切术,形成2mm缺损.羊膜间充质干细胞(促红细胞生成素协同治疗为Ⅳ组,无促红细胞生成素协同治疗为Ⅲ组),生理盐水(促红细胞生成素协同治疗为Ⅱ组,无促红细胞生成素的为Ⅰ组)移植入缺损处.用损伤后3个月内的临床运动评分,8周时的细胞增殖、免疫组织化学结果 评价脊髓的修复.结果 临床运动评分,Ⅳ组(12.01±0.62)恢复优于Ⅲ组(9.47±0.36)、Ⅱ组(7.57±0.28),差异有统计学意义(P<0.01).并且Ⅳ组损伤区具有更高密度的5-溴脱氧尿嘧啶核苷(BrdU)阳性细胞(25.34±3.51),损伤脊髓远端有更高水平的抗微管相关蛋白-2(MAP-2)表达(8.47±0.87),其差异有统计学意义(P<0.01).结论 促红细胞生成素和羊膜间充质干细胞对于脊髓损伤有协同治疗作用.

Abstract：

Objective To evaluate the combined effects of erythropoietin and amnion-derived mesenchymal stem cells on spinal cord injury (SCI).Methods In 60 SD rats (n=15 in each group) transverse hemi-section at the T11 level was carried out, leaving an approximately 2-mm gap between the distal and proximal ends of the cord. Amnion-derived mesenchymal stem cells embedded in fibrin glue treated with or without erythropoietin (groups Ⅲ and Ⅳ) or fibrin glue with or without erythropoietin (groups Ⅰ and Ⅱ) were transplanted into the gap in the injured spinal cord. Spinal cord regeneration was assessed using a clinical locomotor rating scale scores (BBB scores) every week after injury, and immunohistochemistry 8 weeks after injury.Results Regeneration was more advanced in group Ⅳ (12.01±0.62) than in groups Ⅲ (9.47±0.36) or Ⅱ (7.57±0.28) according to the clinical motor score (P<0.01). Higher densities of bromodeoxyuridine (25.34±3.51) in the injured area and higher expression levels of MAP-2 (8.47±0.87) over the distal end of the injured spinal cord were observed in group Ⅳ than in groups Ⅱ or Ⅲ (P<0.01).Conclusion This synergy between erythropoietin and amnion-derived mesenchymal stem cells may be due to increased proliferation of progenitor cells in the injured area and increased expression of neuronal stem cell markers in the distal end of the injured cord.     

神经调节素对缺血再灌注损伤大鼠脊髓MMP-9和TIMP-1表达的影响

目的:观察神经调节素-1β(neuregulin-1β,NRG-1β)对大鼠脊髓缺血再灌注损伤后脊髓组织基质金属蛋白酶-9(MMP-9)、金属蛋白酶组织抑制剂-1(TIMP-1)表达的影响,并初步探讨其作用与机制。方法:48只SD大鼠随机分为对照组(n=16)、缺血再灌注组(模型组,n=16)、NRG-1β治疗组(n=16),对照组仅分离暴露腹主动脉,其余两组采用腹主动脉阻断法制备动物模型。治疗组在打开动脉夹后立即经尾静脉注射NRG-1β(10μg/kg),缺血再灌注模型组在打开动脉夹后立即经尾静脉注射等量的0.1mol/L的PBS缓冲液。于取材前3min根据改良Tarlov评分标准进行神经功能评分。分别于术后3h、6h、12h、24h取材(每个时间点4只),HE染色观察脊髓病理变化,免疫组化和Real-time PCR分别检测MMP-9、TIMP-1蛋白和m RNA水平的表达。结果:模型组在术后各时间点的Tarlov评分较对照组显著下降(P0.05),治疗组在术后6h、12h、24h的Tarlov评分较模型组显著增高(P0.05)。HE染色显示模型组和治疗组均存在脊髓组织损伤,但治疗组较模型组减轻。免疫组化结果显示,对照组未见MMP-9、TIMP-1阳性表达细胞;模型组MMP-9免疫阳性细胞数(个/高倍视野)在术后3h、6h、12h、24h分别为9.00±1.63、23.80±1.71、28.30±1.50、34.80±2.63,治疗组分别为8.50±0.58、17.80±0.96、20.80±3.50、30.00±2.16,其中6h、12h、24h治疗组与模型组相比阳性细胞数明显减少(P0.05)。模型组TIMP-1免疫阳性细胞数(个/高倍视野)在术后3h、6h、12h、24h分别为11.80±0.96、12.30±1.50、7.80±0.96、7.80±1.50,治疗组分别为12.30±0.96、13.80±0.96、10.50±1.73、10.30±0.96,其中12h、24h治疗组与模型组相比阳性细胞数明显增多(P0.05)。对照组MMP-9在术后3h、6h、12h、24h的m RNA表达量分别为4.93±0.21、4.95±0.24、4.96±0.25、4.98±0.23,模型组分别为5.38±0.25、6.53±0.31、6.87±0.29、7.53±0.33,治疗组分别为5.35±0.26、5.56±0.22、5.74±0.27、5.90±0.31,其中6h、12h、24h模型组与对照组比较MMP-9的m RNA表达量明显增加(P0.05),6h、12h、24h治疗组MMP-9的m RNA表达量较模型组明显减少(P0.05)。对照组TIMP-1在术后3h、6h、12h、24h的m RNA表达量分别为4.74±0.23、4.76±0.21、4.73±0.25、4.76±0.24,模型组分别为4.53±0.32、4.62±0.21、3.83±0.20、3.65±0.32,治疗组分别为4.55±0.26、4.65±0.27、4.28±0.22、4.25±0.24,其中12h、24h模型组与对照组比较TIMP-1的m RNA表达量明显减少(P0.05),12h、24h治疗组TIMP-1的m RNA表达量较模型组明显增加(P0.05)。结论 :神经调节素可在大鼠脊髓缺血再灌注损伤过程中发挥神经保护作用,该作用的实现可能与MMP-9的表达下调和TIMP-1的表达上调有关。     

Prevention of reperfusion injury of the spinal cord in aortic surgery: An experimental study

Purpose We designed an experimental study to show the effects of some agents in order to prevent reperfusion injury of the spinal cord. Methods Twenty rabbits were used and were divided into two groups in our study. Infrarenal abdominal aortic occlusion, between renal arteries and iliac bifurcations, was applied to the subjects in group 1 for only 30 min; in the group 2 subjects, on the other hand, intra-aortic diltiazem, N-acetylcysteine, and catalase combinations were applied after infrarenal abdominal aortic occlusion. The spinal cord functions of the subjects were assessed at the 48th hour after the operation according to Tarlov scoring, then cord tissue samples were taken for biochemical and histopathological studies. Results The group 2 subjects had better neurological functions than group 1 subjects (P < 0.01). In group 2; superoxide dismutase and glutathione peroxidase levels increased, while malondialdehyde and xanthine oxidase levels decreased as compared with group 1 (P < 0.05). A histopathological examination showed the group 2 samples to have fewer bleeding points and less neuron loss. Conclusions We concluded that antioxidant agent combinations (diltiazem, N-acetylcysteine, and catalase) applied after ischemia might thus help protect the spinal cord against ischemia and reperfusion injury.