周围神经缺血再灌注损伤动物模型的改良

目的研究周围神经缺血再灌注损伤动物模型的改良与建立。方法采用无损伤动脉夹暂时阻断大鼠一侧髂总动脉起始处血流,同时夹闭髂内、髂外动脉,一段时间后打开动脉夹,观察不同缺血再灌注时间下动物肢体功能情况,以及周围神经缺血导致的脊髓电镜下超微结构的改变,明确改良动物模型的实验效果。结果缺血时间的延长动物后肢的瘫痪症状逐渐加重。电镜观察脊髓神经元显示随再灌注时间的延长,神经元损害明显加重。结论用无损伤动脉夹阻断一侧髂总动脉和髂内、髂外动脉的周围神经缺血再灌注损伤的动物模型是对以往模型的改良。该模型制备操作简单,对动物的损伤更小,可得到理想的实验效果。     

Differential expression of heat shock proteins 70-1 and 70-2 mRNA after ischemia-reperfusion injury of rat kidney

Ischemia-reperfusion injury in the kidney is known to cause induction of the inducible form of the 70 kDa heat shock protein HSP70i (or HSP72). However, knowledge of the expressional regulation of the two coding genes for HSP70i –HSP70-1 gene and HSP70-2 gene – is very limited. We investigated the time course of HSP70-1 and -2 mRNA expression and its relation to cellular ATP levels in the renal cortex after different periods of unilateral warm renal ischemia (10–60 min) and reperfusion (up to 60 min) in 10-week-old male Wistar rats. Immediately after ischemia there was a significant induction of both HSP70i genes. While HSP70-1 expression constantly increased (up to 4-fold) during reperfusion, even to a higher extent with prolongation of ischemia, HSP70-2 mRNA – which was generally expressed at a far lower level than HSP70-1 mRNA – was strongly induced (3-fold) during reperfusion only after brief periods (10 min) of ischemia. Cellular ATP levels rapidly dropped to 5% with ischemia and the pattern of recovery during reperfusion significantly depended on the duration of the ischemic period, thus showing a good relation with the heat shock (protein) gene expression. We conclude that HSP70-2 is the more sensitive gene with a lower activation threshold by mild injury, while the HSP70-1 gene mediates the major response of heat shock protein induction after severe injury. Received: 16 November 1998 / Accepted: 11 March 1999     

卡托普利对缺血-再灌注鼠心肌一氧化氮及其合酶活性的影响

目的　研究一氧化氮 (NO)和一氧化氮合酶 (NOS)在心肌再灌注损伤中的作用 ,探讨卡托普利(captopril)对缺血 -再灌注鼠心肌保护的机制。　方法　采用 L angendorff离体鼠心灌流模型 ,将 18只 SD大白鼠随机分为 3组 (每组 6只 ) ,对照组、缺血 -再灌注组、卡托普利组。观察心肌 NOS同工酶活性、过氧化物歧化酶活性、丙二醛含量、肌酸激酶含量和冠脉流出液 NO的变化。　结果　缺血 -再灌注组与对照组比较心肌诱导型 NOS(i NOS)活性增高 (P<0 .0 0 1) ,而心肌原生型 NOS(c NOS)活性及总 NOS活性显著降低 (P<0 .0 0 1,0 .0 5 ) ,冠脉流出液 NO含量下降(P<0 .0 1)。卡托普利组再灌注 30分钟 ,心肌 i NOS活性低于缺血 -再灌注组 (P<0 .0 1) ,c NOS活性和总 NOS活性高于缺血 -再灌注组 (P<0 .0 1,0 .0 5 ) ,再灌注期间冠脉流出液 NO水平高于缺血 -再灌注组 (P<0 .0 1) ,心肌损伤较缺血 -再灌注组减轻。　结论　心肌 NOS同工酶活性及 NO产生的失常是心肌再灌注损伤的重要机制之一 ,卡托普利可通过调节心肌 NOS同工酶活性 ,维持正常的 NO水平 ,起到心肌保护作用。     

右美托咪定对大鼠离体肺缺血-再灌注损伤时ERK 1/2和Akt激活的影响

目的评价右美托咪定对大鼠离体肺缺血-再灌注损伤(lung ischemia-reperfusion injury,LIRI)时胞外信号调节激酶(ERK 1/2)和丝氨酸/苏氨酸蛋白激酶(Akt)激活的影响。方法成年雄性SD大鼠45只,随机分为三组:对照组(C组)、缺血-再灌注组(IR组)和右美托咪定组(DEX组),每组15只。C组大鼠离体肺在IL-2离体肺灌流系统内维持正常的生理活动,只通气和灌流150 min;IR组和DEX组大鼠离体肺在IL-2离体肺灌流系统中维持15 min后,停止通气和灌流60min后再通气和复灌75 min;DEX组复灌开始时于离体灌流液中加入右美托咪定10 nmol/L。C组和IR组分别于灌流75 min和复灌开始时在离体灌流液中加入等体积生理盐水。检测肺泡损伤率(IAR)。采用逆转录-聚合酶链式反应(RT-PCR)法测定肺组织ERK 1/2、Akt m RNA表达量,Western blot法测定磷酸化-ERK(p-ERK 1/2)、磷酸化-Akt(p-Akt)蛋白含量。结果与C组比较,IR组和DEX组IAR、肺组织ERK 1/2、Akt m RNA表达量和p-ERK 1/2及p-Akt蛋白含量均明显升高(P0.05);与IR组比较,DEX组IAR、肺组织ERK 1/2、Akt m RNA表达量和p-ERK1/2及p-Akt蛋白含量均明显降低(P0.05)。结论右美托咪定可减轻大鼠离体LIRI,其机制可能与其抑制ERK 1/2和Akt的激活有关。     

七氟醚后处理对糖尿病大鼠脑缺血-再灌注损伤的影响

目的研究七氟醚后处理对糖尿病大鼠脑缺血-再灌注损伤的影响。方法雄性SD大鼠32只,3.0~3.5月龄,体重280~320 g,采用随机数字表法分为四组:非糖尿病缺血-再灌注对照组(NDC组)、糖尿病缺血-再灌注对照组(DC组)、非糖尿病缺血-再灌注七氟醚后处理组(NDS组)和糖尿病缺血-再灌注七氟醚后处理组(DS组),每组8只。采用栓线法和链脲佐霉素制备缺血-再灌注损伤大鼠模型和糖尿病大鼠模型。缺血2 h,再灌注24 h后,进行大鼠神经缺损评分,采用TTC法测定脑梗死体积,Western blot法测定血管生成素-1(angiopoiettin-1,Ang-1)蛋白含量。结果DC组神经缺损评分、脑梗死体积百分比明显高于NDC组,Ang-1蛋白含量明显低于NDC组(P0.05);NDS组神经缺损评分、脑梗死体积百分比明显低于NDC组,Ang-1蛋白含量明显高于NDC组(P0.05);DS组神经缺损评分、脑梗死体积百分比明显低于DC组,Ang-1蛋白含量明显高于DC组(P0.05)。结论大鼠脑缺血-再灌注后,糖尿病可加重神经缺损,增大脑梗死体积,减少Ang-1蛋白含量;七氟醚可减轻神经缺损,减小脑梗死体积,增加Ang-1蛋白含量;七氟醚后处理减轻大鼠脑缺血-再灌注损伤与Ang-1蛋白含量增加有关。     

Mixed agonistic-antagonistic cytokine response in whole blood from patients undergoing abdominal aortic aneurysm repair

Objective: To characterize the impact of abdominal aortic aneurysm repair (AAAR) on spontaneous as well as lipopolysaccharide (LPS)-induced gene expression of pro- and anti-inflammatory cytokines. Design: Prospective, controlled in vivo / ex vivo study. Setting: University hospital. Patients and interventions: Whole blood from 14 consecutive patients undergoing AAAR withdrawn prior to surgery (T1), at the end of ischemia (T2), 90 min after declamping (T3) and on the first postoperative day (T4) was cultured in the absence or presence of LPS. Five patients undergoing elective inguinal hernia repair served as controls. Measurements and results: While tumor necrosis factor (TNF), Interleukin (IL)-1 and IL-10 plasma concentrations did not increase significantly, IL-6 was elevated at each time point, as compared with T1. Despite the spontaneous release of trace amounts of IL-6, the ability of cultured whole blood to mount a cytokine response in vitro to LPS was impaired for all cytokines studied at T2 (TNF –62 %, IL-1 –51 %, IL-6 –20 %, IL-10 –51 %). The stimulated IL-6 response was restored early after declamping (T3: + 56 %) and enhanced 1 day after operation (T4: + 144 %). In contrast, stimulated TNF and IL-1 responses remained depressed at T3 (TNF –48 %, IL-1 –64 %) and T4 (TNF –40 %, IL-1 –24 %). A biphasic pattern was observed for IL-10 with initial depression at T3 (-51 %) and restoration at T4 ( + 40 %). Among the different cytokines monitored, only impaired TNF responsiveness at early reperfusion (T3) correlated with the postoperative course, as reflected by APACHE II. Cytokine response to LPS was maintained or even increased during and after surgery in the whole blood from patients undergoing hernia repair. Conclusions: Despite consistent development of clinical signs of systemic inflammatory response syndrome (SIRS) and spontaneous release of IL-6 abdominal aortic aneurysm repair produces a state of impaired pro-inflammatory cytokine response upon a subsequent in vitro Gram-negative stimulus. This early impairment of TNF responsiveness seems to correlate with an unfavorable postoperative course. Received: 17 April 1998 Final revision received: 22 July 1998 Accepted: 17 August 1998     

补体在大鼠脑缺血-再灌注损伤中的作用

目的观察补体C1q和C3d在大鼠脑缺血-再灌注损伤过程中表达水平的动态变化，探讨其与脑水肿、脑损伤的相关性和作用机制。方法采用线栓法制备大鼠大脑中动脉闭塞(MCAO)模型，缺血2h后再灌注。应用免疫组化法检测脑内补体C1q和C3d蛋白的表达，记录大脑神经功能缺失程度、脑组织含水量的动态变化。结果局灶性脑缺血-再灌注损伤后脑内补体C1q和C3d蛋白的表达水平逐渐增加，至缺血-再灌注后24h达高峰，至再灌注后120h左右恢复至正常水平。脑组织含水量在缺血-再灌注24～72h达高峰。神经功能缺失最重的时间点出现在缺血-再灌注后24h。补体C1q和C3d的表达水平与脑水肿和神经功能缺失呈正相关。结论脑缺血-再灌注后补体激活参与其损伤过程，抑制补体激活有望成为新的治疗脑缺血-再灌注损伤的靶点。     

全脑缺血再灌后bFGF对小鼠额叶、海马神经元保护作用的研究

目的探讨碱性成纤维细胞生长因子（Basic fibroblast growth factor，bFGF）在全脑缺血再灌流后不同时期对小鼠额叶皮层、海马神经元的保护作用。方法选择健康雄性昆明小鼠45只，随机分为假手术组5只、对照组20只、bFGF治疗组20只。用组织病理学方法检测全脑缺血后对照组及治疗组小鼠额叶皮层、海马组织病理学改变。结果bFGF治疗组额叶皮层、海马损伤神经元明显减少，与对照组比较P〈0．05。结论bFGF对脑缺血后神经元有保护及修复作用，bFGF能有效降低缺血后脑组织损伤程度。     

血塞通预处理对心肌缺血再灌注损伤的早期保护作用

目的观察血塞通预处理对大鼠心肌缺血再灌注(I/R)损伤的早期保护作用,并研究其可能机制.方法采用开胸冠状动脉结扎建立缺血再灌注模型,25只雄性SD大鼠随机分为假手术组,缺血再灌注组(I/R组),缺血预处理组(IPC组),血塞通预处理组(PNS预处理组).再灌注后2 h测定各组血清肌酸磷酸激酶-MB(CK-MB)含量以及心肌细胞凋亡情况和心肌细胞Bcl-2和Bax蛋白的表达,并观察心肌超微结构变化.结果IPC组及PNS预处理组血清CK-MB均明显低于I/R组(P＜0.05).IPC组及PNS预处理组TUNEL阳性细胞数,Bax阳性细胞数均明显低于I/R组(P＜0.05).和I/R组相比,IPC组及PNS预处理组心肌超微结构损伤减轻.结论PNS预处理后心肌细胞凋亡减少,心肌细胞损伤减轻,对I/R损伤产生有和缺血预处理类似的早期保护作用.     

心肺复苏后大鼠神经细胞凋亡的实验研究

目的：研究全脑缺血再灌注后大鼠脑神经细胞的凋亡情况。方法：Sprague Dawley 大鼠28只，雌雄各半，随机分5组，即对照组(假手术组)以及复苏后3、6、12、24h组，对照组4只，其余每组6只。采用窒息合并冰氯化钾停跳液致大鼠心跳骤停-心肺复苏模型，停跳5min后开始心肺复苏，采用TUNEL方法和透射电镜观察复苏后神经细胞的凋亡情况。结果:复苏后3h大鼠脑皮质神经元就出现细胞凋亡，复苏后24h海马区TUNEL阳性率为6．0％。结论:细胞凋亡可能是大鼠全脑缺血再灌注后神经细胞损伤的主要机制之一。