西地那非在犬肺移植缺血再灌注损伤中的作用

目的 观察5型磷酸二酯酶抑制剂西地那非在肺移植缺血再灌注损伤中的作用.方法 12对体重匹配杂种犬随机分为对照组(n=6)和实验组(n=6),利用同种异体犬左单肺移植模型,实验组供肺肺动脉阻断前经主肺动脉注射西地那非1.0 mg/kg体重,移植后持续泵入西地那非每小时0.3 mg/kg体重,对照组给予等容量生理盐水.观察移植前及移植后30、60、120、180min移植肺上叶静脉血氧分压(PO2)变化,于移植后120 min取肺组织,测丙二醛(MDA)、髓过氧化物酶(MPO)及组织含水量(H)并观察组织形态学变化.结果 实验组PO2明显高于对照组(293±52比160±45,P＜0.05);供肺组织MDA(0.25±0.09比0.50±0.09)、MPO含量(0.13±0.06比0.25±0.09)及含水量(71.59±4.63比78.04±3.73)明显低于对照组(P＜0.05);组织形态学显示实验组损伤程度较对照组轻.结论 西地那非在供肺保存及再灌注损伤中具有肺保护作用.     

肺移植缺血再灌注损伤的治疗进展

本文综述了肺移植缺血再灌注损伤的防治,包括：移植肺的灌注;对移植肺有保护作用的其它物理因素（缺血预处理,氧浓度,胆碱能抗炎通路）;对移植肺有保护作用的一些药物;转基因治疗。     

银杏叶提取物对大鼠移植肺缺血再灌注的影响

本研究旨在观察银杏叶提取物(Egb761)对大鼠肺移植后血清及移植肺丙二醛(MDA)、谷光甘肽(GSH)及肺组织湿，干重比的影响，探讨Egb761对移植肺缺血再灌注损伤的作用。     

缺血-再灌注肺损伤动物模型的建立方法

缺血 再灌注肺损伤是指肺组织或其他组织器官遭受一定时间缺血后恢复血液灌流 (再灌注 ) ,肺组织损伤程度迅速增剧的病理现象。根据缺血组织器官的不同 ,再灌注肺损伤可分为两大类病因 ,一类是肺血管缺血后再灌注产生的肺组织损伤 ,如肺栓塞溶栓治疗、肺血栓内膜切除术、心肺移植术等 ;另一类为肺外组织器官缺血后再灌注导致肺组织损伤 ,如肢体手术、腹主动脉瘤手术等。由于血运重建后 ,反而引起肺组织损伤加重 ,有悖于治疗目的 ,因此开展缺血 再灌注肺损伤的研究和防治已愈来愈受到人们的重视 ,而建立良好的动物模型又是研究缺血 再灌注…     

姜黄素对大鼠单肺移植缺血再灌注损伤的保护作用

目的观察大鼠单肺移植缺血再灌注肺损伤肺功能改变及姜黄素（CUR）干预作用。方法建立大鼠原位异体左单肺移植模型。纯种雄性SD大鼠120只，随机分两组，每组又分三个亚组（n=12）：假手术组、载体组、CUR组，分别在缺血4h、再灌注2h和24h处死大鼠，测量移植肺损伤病理评分、氧合指数、肺湿干重比（W／D）、伊文思篮染料（EBD）含量。结果移植肺组织病理学主要表现为肺水肿，炎症细胞浸润，出血。与假手术组比较，再灌注2h，移植肺氧合指数从358．3下降到153．7，W／D从3．7增加到5．6，EBD含量从381．0μg／g干重增加到1172．3μg／g干重；再灌注24h后，氧合指数从394．2下降到102．3，移植肺W／D从3．8增加到6．6；EBD含量从387．5μg/g干重增加到927．5μg/g干重。供体和受体大鼠经CUR预处理后，明显减少缺血4h，再灌注2和24h的移植肺组织学病理评分，肺泡毛细血管通透性，湿干重比，改善气体交换。结论大鼠单肺移植后缺血再灌注损伤（IRI）肺功能学改变主要表现为肺泡毛细血管内皮损伤导致的通透性肺水肿及由此导致的氧合功能下降。CUR对大鼠单肺移植缺血再灌注肺损伤具有保护作用。     

肺缺血再灌注损伤的机制和防治进展

本文对肺缺血再灌注损伤的发生机制与防治进展进行了较为系统的阐述。     

缺血后处理对供体犬肺再灌注损伤的影响

目的 观察供体犬肺再灌注后早期脂质过氧化反应的变化,了解缺血后处理对供体犬肺植入后功能的影响.方法 随机选取12对比咯犬,组成供、受体,随机分成2组.对照组:6对犬,按常规进行供受体左侧异体单肺移植,不予缺血后处理的干预.缺血后处理组:6对犬,进行供受体常规左侧异体单肺移植,再灌注早期实施3个周期的10 s再灌-10 s再阻断、总时程1 min的缺血后处理.于供肺再灌注后1、2 h两个时间点采集供肺标本检测超氧化物歧化酶(SOD)的活性、丙二醛(MDA)的含量.光镜下观察供肺植入后1、2 h两个时间点肺组织的病理变化.结果 术后实验犬均存活.植入供体肺平均用时(35.92±1.73)min.缺血后处理组在1、2h时间点的供肺组织SOD活性水平较对照组升高、MDA含量较对照组减低,差异有统计学意义(P<0.05).缺血后处理组肺组织光镜下观察在各时间点的炎症反应均较对照组的变化轻微.结论 缺血后处理可以抑制再灌注时氧自由基的堆积,从而减少供肺的缺血冉灌注损伤,改善供肺植入后的功能.     

腺苷对犬心肺联合移植供肺缺血-再灌注损伤的保护作用

目的 研究腺苷(ADO)对犬心肺联合移植供肺缺血-再灌注(I/R)损伤的保护作用.方法 建立犬心肺联合移植模型,将实验分为心肺联合移植对照组(对照组)和腺苷组,观察恢复血流灌注后30、60、90和120 min时两组犬动脉血氧分压(PaO2)的变化;测定缺血前10 min、缺血后10 min、120 min、再灌注后10 min、60 min供肺组织一氧化氮(NO)含量;在恢复血流灌注60 min后,取供肺组织为标本,检测肺组织中髓过氧化物酶(MPO)活力、丙二醛(MDA)含量、超氧化物歧化酶(SOD)含量以及肺组织湿干重比(W/D);HE染色光学显微镜下观察病理变化.结果 (1)在各时间点腺苷组PaO2值较对照组明显升高(P＜0.05);(2)与缺血前比较,缺血后120min、再灌注后10min和60min的肺组织NO含量均显著降低(P＜0.05),而腺苷组缺血后120 min、再灌注后10 min和60 min肺组织NO含量显著高于对照组(P＜0.05);(3)腺苷组肺组织中MPO活力、MDA含量、肺组织W/D显著低于对照组,SOD含量显著高于对照组(P＜0.05);(4)病理切片观察显示对照组的肺组织呈严重的炎性细胞浸润及肺水肿形成,而腺苷组的病变程度较对照组轻微.结论 在心肺联合移植过程中应用ADO,对供肺的缺血-再灌注损伤有保护作用.     

内皮素受体拮抗剂PD142893对大鼠肺移植早期缺血再灌注损伤的影响

目的探讨PD142893对大鼠肺移植早期缺血再灌注损伤的保护作用及其机制。方法大鼠行原位左肺移植,随机分成两组,移植前实验组尾静脉注入PD142893(0．1 mg/kg·ml~(-1)) 1 ml,移植后0、1、2、6、12及24 h,采集标本,各5只大鼠。检测动脉血气、血浆内皮素(ET)-1和白细胞介素(IL)-6水平,左肺常规病理切片并用脱氧核苷酸转移酶介导的缺口末端标记(TUNEL)法检测凋亡细胞并计数,检测肺湿/干重比。结果两组对比,肺静脉血氧分压,除0、24 h外各时间点实验组较高,差异有统计学意义(P＜0．05)；血浆IL-6水平,除0 h外各时间点对照组较高(P＜0．05)；ET-1水平实验组较高(P＜0．05)。光镜下对照组肺组织严重的白细胞浸润及肺间质高度淤血水肿,肺泡腔内渗出明显,实验组病变程度轻微,细胞凋亡指数和肺湿/干重比低于对照组(P＜0．05)。结论PD142893能减轻大鼠肺移植早期缺血再灌注损伤,机制与减轻肺间质水肿及炎症反应有关。     

BQ123对肺移植早期缺血再灌注损伤保护作用的实验研究

目的　研究内源性内皮素（ Ｅ Ｔ）１ 对肺移植早期缺血再灌注损伤的影响及 Ｅ Ｔ Ａ 受体阻断剂 Ｂ Ｑ１２３ 对其病理过程的保护作用。方法　以家犬（ 保存８ 小时） 左肺移植模型观察缺血再灌注。损伤过程中内源性 Ｅ Ｔ１ 产生及 Ｂ Ｑ１２３ 对其血流动力学、肺功能的作用。结果　 Ｂ Ｑ１２３ 组和对照组的平均动脉压、左房压、中心静脉压及组织形态学差异无显著性; Ｂ Ｑ１２３ 组平均肺动脉压、肺血管阻力指数及血清 Ｅ Ｔ１ 浓度明显低于对照组（ Ｐ ＜ ０ ．０１） ,心脏指数、动脉血氧分压明显高于对照组（ Ｐ ＜ ０ ．０１） ,而动脉二氧化碳分压明显低于对照组（ Ｐ ＜ ０ ．０１） ; Ｂ Ｑ１２３ 组肺组织含水百分比明显低于对照组（ Ｐ ＜０ ．０１） 。结论　 Ｂ Ｑ１２３ 对肺移植早期出现的缺血再灌注损伤具有保护作用。     

离体人睾丸缺血再灌注损伤模型

目的：建立离体人睾丸的缺备再灌注（I／R）损伤模型，为研究抗I／R损伤药物的作用及机理提供一实质器官灌注模型。方法：采用１３例捐赠尸睾，用250ml0℃-4℃高渗枸橼酸盐嘌呤液灌洗后冷存，再以500ml37℃该液进行再灌注，不同时间点取材作组织学及酶组织化学检查。结果：4℃冷缺血12h开始出现血管仙皮细胞肿胀、变圆、空泡样变，24h内皮细胞变性脱落，睾丸曲细精管基膜与生精上皮剥离，生精细胞变性脱落，间质水肿等，病变随冷缺血时间延长而加重。酶组化结果显示，单纯冷保存18h后，睾丸组织乳酸脱氢酶（LDH）活性升高，琥珀酸脱氢酶（SDH）活性24h后升高，经37℃复温再灌注后损伤明显加重。结论：离体人睾丸可替代人体其它实质器官作为研究I／R损伤的离体灌注模型。     

人参皂甙Rb1对肺缺血再灌注损伤的保护作用

目的探讨人参皂甙Ｒｂ１对肺缺血再灌注损伤的保护作用。方法按肺移植供肺获取和保存的方法，对３５只家兔的肺分别获取，保存；然后采用体外装置，建立体外肺缺血再灌注损伤模型。在即将再灌流前，将不同剂量的Ｒｂ１加入到５０ｍｌ再灌流血液中。结果Ｒｂ１可使肺组织中超氧化物歧化酶（ＳＯＤ）含量升高，丙二醛（ＭＤＡ）含量降低；使肺动脉压（ＰＡＰ）降低，湿肺干肺比重降低和改善肺组织病理变化。Ｒｂ１在再灌流血液中浓度为８０ｍｇ／Ｌ时，已有明显效果。结论Ｒｂ１对肺缺血再灌注损伤具有明显的保护作用。     

A New Model for the Assessment of Lung Allograft Ischemia/Reperfusion Injury

Lung edema is the main clinical manifestation of reperfusion injury following lung transplantation. The evaluation of strategies to prevent this injury is of high clinical importance. Therefore we developed a large-animal model to study the mechanisms of ischemia/reperfusion injury including dynamics of posttransplant reperfusion edema and their prevention. Left lung allotransplantation was performed in 6 weight-matched pigs (25-31 kg). Donor lungs were flushed with 1.5 L low-potassium dextran (LPD) solution (4^oC) and preserved for 20 h at 1^oC. One hour after reperfusion the recipient contralateral right lung was excluded from perfusion and ventilation to assess graft function only. Extravascular lung water index (EVLWI), intrathoracic blood volume (ITBV), and cardiac output (CO) were assessed (q = 30 min) with a lung water computer (Cold Z-021, Partig, Munich, Germany) by the thermo-dye technique during a 5-h observation period. Gas exchange (FIO₂ = 1.0) was measured hourly, and hemodynamics were monitored continuously. The EVLWI of the recipient contralateral lung together with the donor left lung at the time of reperfusion was 6.5 +/- 1.1 ml/kg, increasing to 7.1 +/- 1.0 ml/kg at 60 min after reperfusion. After occlusion of the recipient right lung, EVLWI in the graft further increased within 80 min from 8.1 +/- 0.5 ml/kg to a peak of 11.4 +/- 1.3 ml/kg, followed by a decrease to 8.5 +/- 0.8 ml/kg at 5 h after reperfusion in 5 of 6 animals. In 1 animal a severe alveolar edema developed with subsequent deterioration of gas exchange and death 4.5 h after reperfusion. In this animal, peak EVLWI reached 16.8 ml/kg, PaO₂ deteriorated from 60.1 to 7.8 kPa, and CO decreased from 3.1 to 1.4 L/min. In all other animals, ITBV (515 +/- 51 ml), left atrial pressure (LAP), central venous pressure (CVP), and CO (2.9 +/- 0.3 L/min) were stable during the 5-h assessment period. We conclude that EVLWI measurement is a reliable and very sensitive method to quantify lung allograft reperfusion edema. It may prove useful in early assessment of lung allograft reperfusion injury in the clinical setting and in experimental models.     

Matrix Metalloproteinase Inhibition Decreases Ischemia-Reperfusion Injury After Lung Transplantation

Increased microvascular permeability and extravasation of inflammatory cells are key events of lung ischemia-reperfusion (IR) injury. The purpose of this study was to investigate the role of matrix metalloproteinases (MMP) in IR-induced alveolar capillary membrane disruption after experimental lung transplantation. We used a rat model of lung orthotopic transplantation (n = 86) with a prolonged cold ischemic phase. MMP2 and MMP9 were elevated 4 h after the onset of ischemia and further increased during reperfusion. Compared to sham values, the alveolar-capillary membrane permeability increased by 105% and 82.6% after 4 h of ischemia and 2 h or 24 h of reperfusion, respectively. A 4- and 5-fold increase of the infiltration of ischemic tissue by neutrophils was also observed after 2 h and 24 h of reperfusion. The PO2/FIO2 ratio dropped significantly from 244 to 76.6 after 2 h of reperfusion and from 296.4 to 127.6 after 24 h of reperfusion. A nonselective inhibitor of MMP, administered to the rats and added to the preservation solution, reduced significantly the alveolar-capillary leakage, the transmigration of neutrophils and improved gas exchanges in animals submitted to 4 h of ischemia combined with 2 h or 24 h of reperfusion. We conclude that inhibition of MMP attenuates IR injury after experimental lung transplantation.     

Nitrite Reduces Acute Lung Injury and Improves Survival in a Rat Lung Transplantation Model

Ischemia/reperfusion injury (IRI) is the most common cause of early mortality following lung transplantation (LTx). We hypothesized that nitrite, an endogenous source of nitric oxide (NO), may protect lung grafts from IRI. Rat lung grafts were stored in preservation solution at 4°C for 6 hours. Both grafts and recipients were treated with nitrite. Nitrite treatment was associated with significantly higher levels of tissue oxygenation, lower levels of cytokines and neutrophil/macrophage infiltration, lower myeloperoxidase activity, reduced oxidative injury and increased cGMP levels in grafts than in the controls. Treatment with either a nitric oxide scavenger or a soluble guanylyl cyclase (sGC) inhibitor diminished the beneficial effects of nitrite and decreased cGMP concentrations. These results suggest that nitric oxide, generated from nitrite, is the molecule responsible for the effects of nitrite via the nitric oxide/sGC/cGMP pathway. Allopurinol, a xanthine oxidoreductase (XOR) inhibitor, abrogated the protective effects of nitrite, suggesting that XOR is a key enzyme in the conversion of nitrite to nitric oxide. In vitro experiments demonstrated that nitrite prevented apoptosis in pulmonary endothelial cells. Nitrite also exhibits longer survival rate in recipients than control. In conclusion, nitrite inhibits lung IRI following cold preservation and had higher survival rate in LTx model.     

己酮可可碱在肺缺血-再灌注损伤中的作用

目的　探讨己酮可可碱 (PTX)对肺缺血 -再灌注损伤的保护作用。　方法　 72只大鼠随机分为 3组 ,每组 2 4只。 组 :未行缺血及再灌注处理 ; 组 :行左肺缺血和再灌注处理 ; 组 :行左肺缺血和再灌注处理 ,并给予己酮可可碱。采用在体肺温缺血 -再灌注损伤的模型 ,于缺血 45分钟、再灌注 1小时、2小时和 4小时进行动脉血气分析、肺组织含水量、支气管肺泡灌洗液白蛋白含量、血浆和左肺组织丙二醛、左肺组织和支气管肺泡灌洗液髓过氧化物酶(MPO)活性测定。　结果　 组再灌注 2小时和 4小时动脉血氧分压显著降低 ,各时间点左肺含水量、支气管肺泡灌洗液白蛋白含量、血浆丙二醛、左肺组织、支气管肺泡灌洗液中髓过氧化物酶均显著升高 ,PTX可改善上述指标变化。结论　 PTX通过抑制中性粒细胞肺内聚集 ,减轻肺血管内皮细胞损伤程度 ,而防止损伤的发展     

Experimental orthotopic lung transplantation model in rats with cold storage

This report describes a new experimental procedure, a rat unilateral, orthotopic lung transplantation with cold storage, and evaluates its relevancy and reliability to study the early events during cold ischemia/reperfusion (I/R) injury. This model, using the cuff technique, does not require extensive training and is relatively easy to be established. The model can induce reproducible degrees of pulmonary graft injury including impaired gas exchange, proinflammatory cytokine upregulation, or inflammatory infiltrates, depending on the preservation time. The results are consistent with the previous clinical evidence, thus suggesting that this model is a valid and reliable animal model of cold I/R injury. A. Nakao and K.R. McCurry contributed equally to this work.     

A Mouse Model of Orthotopic Vascularized Aerated Lung Transplantation

Outcomes after lung transplantation are markedly inferior to those after other solid organ transplants. A better understanding of cellular and molecular mechanisms contributing to lung graft injury will be critical to improve outcomes. Advances in this field have been hampered by the lack of a mouse model of lung transplantation. Here, we report a mouse model of vascularized aerated single lung transplantation utilizing cuff techniques. We show that syngeneic grafts have normal histological appearance with minimal infiltration of T lymphocytes. Allogeneic grafts show acute cellular rejection with infiltration of T lymphocytes and recipient-type antigen presenting cells. Our data show that we have developed a physiological model of lung transplantation in the mouse, which provides ample opportunity for the study of nonimmune and immune mechanisms that contribute to lung allograft injury.