静脉应用抑肽酶对大鼠肺移植模型缺血再灌注损伤的作用

目的 探讨静脉应用抑肽酶对肺移植后肺缺血再灌注损伤的作用和机制.方法 利用移植肺冷缺血14 h建立的大鼠肺移植缺血再灌注损伤模型,考察抑肽酶对缺血再灌注损伤的影响,并检测细胞因子等指标探讨机制.结果 抑肽酶组较对照组移植肺氧合好、湿干比小,同时支气管肺泡灌洗液中白细胞介素(IL)-2[(113±32)μg/L和(162±43)μg/L,P＜0.05]、血清中IL-8[(7.26±1.01)ng/L和(9.43±0.97)ng/L,P＜0.05]和肿瘤坏死因子(TNF)-α[(152.3±36.4)ng/L和(211.6±52.7)ng/L,P＜0.05]、肺组织中髓过氧化物酶活性[(2.36±0.62)U/g和(3.98±0.36)U/g,P＜0.05]都显著降低.结论 静脉应用抑肽酶能够减轻缺血再灌注损伤,机制可能包括:减少IL-2的释放、抑制TNF-α活化和IL-8产生,抑制中性粒细胞的聚集、激活和脱颗粒.     

Activated protein C prevents deleterious effects of remote reperfusion injury caused by intestinal ischemia on wound healing in the left colonic anastomoses: an experimental study in the murine model

Background

Activated protein C (APC) is a serine protease with anticoagulant and antiinflammatory activities. The delaying effects of remote reperfusion injury on the wound-healing process in colonic anastomoses have been previously shown. In this study, we aimed to investigate whether APC protects against deleterious systemic effects of intestinal ischemia/reperfusion (I/R) injury on colonic anastomotic wound healing process.

Methods

Male Wistar-albino rats were randomly allocated into 4 groups, and a left colonic anastomosis was performed in all animals: (1) sham-operated group, simultaneously with left colonic anastomosis, the superior mesenteric artery and collateral branches were divided from the celiac axis, and the inferior mesenteric artery were isolated but not occluded (group 1, n = 12), (2) sham + APC group, identical to group 1 except for APC treatment (100 μg/kg, intravenously, 15 minutes before construction of the colonic anastomosis), (group 2, n = 12), (3) intestinal I/R group, 60 minutes of superior mesenteric ischemia followed by reperfusion (group 3, n = 12), and (4) APC-treated group, (100 μg/kg, intravenously, 15 minutes before reperfusion) (group 4, n = 12). All animals were sacrificed, and colonic anastomotic bursting pressures were measured in vivo on day 7. Tissue samples were obtained for analysis of hydroxyproline contents, nitrate/nitrite levels, and activities of oxidative and antioxidative enzymes. The plasma levels of proinflammatory cytokines and D-dimer were also measured.

Results

Intestinal I/R led to significant decreases in colonic anastomotic bursting pressures, tissue hydroxyproline contents, and activities of antioxidative enzymes, along with increases in tissue nitrate/nitrite levels, activities of oxidative enzymes, and plasma levels of proinflammatory cytokines and D-dimer (P < .05). However, APC treatment led to significant increases in colonic anastomotic bursting pressures, tissue hydroxyproline contents, and activities of antioxidative enzymes, along with decreases in tissue nitrate/nitrite levels, activities of oxidative enzymes, and plasma levels of proinflammatory cytokines and D-dimer (P < .05).

Conclusion

This study clearly showed that APC treatment prevented the delaying effects of remote I/R injury on colonic anastomotic wound healing process. Further clinical studies are required to determine whether APC has a useful role in the enhancement of colonic anastomotic wound healing after particular operations in which I/R injury occurs.     

Activated protein C reduces intestinal injury in an experimental model of necrotizing enterocolitis

Background

Necrotizing enterocolitis is a devastating intestinal disease of premature infants. Although activated protein C (APC) is well defined as a physiologic anticoagulant, emerging data suggest that it also has cytoprotective, antiinflammatory, and antiapoptotic properties. There is no study on active protein C administration for necrotizing enterocolitis in animal models.

Methods

Twenty-one Wistar albino rat pups were divided into 3 groups: group 1 = control; group 2 = hypoxia-reoxygenation and saline; group 3 = hypoxia-reoxygenation and APC (0.2 mg/kg per day) treatment. On the 15th day, hypoxia was induced by placing the pups in a 100% carbon dioxide chamber for 5 minutes. After the hypoxia period, the pups were reoxygenated for 10 minutes with 100% oxygen and returned to their mothers. All pups were killed 4 hours after the hypoxia-reoxygenation period was over. The abdomen was opened, and representative samples of injured areas were taken for histopathologic examination, nitrite levels, apoptosis, and cytokine levels.

Results

On histopathologic examination, injury scores in group 2 animals were found to be significantly higher than in group 3 animals (P = .002). Significantly increased intestinal nitric oxide levels were found in group 2 rats compared with the rats of groups 1 and 3 (P = .001 and P = .001, respectively). The APC treatment was significantly reduced “apoptotic cell death” in the bowel, when compared with vehicle-treated group. The proinflammatory cytokine levels (interleukin [IL]-1β, tumor necrosis factor [TNF]-α, and IL-6) were significantly increased in hypoxia group as compared with control group. The concentration of cytokines, IL-1β, IL-6, and TNF-α was reduced in the APC treatment group.

Conclusion

The APC treatment attenuates hypoxia-reoxygenation induced with intestinal injury and decreased apoptotic cell index in this animal model. The protective effect of APC is associated with its ability to reduce the expression of inflammatory cytokines and nitric oxide.     

肠缺血后肺内一氧化氮合酶的表达及其意义

目的　研究不同时相小肠缺血 /再灌注引起的急性肺损伤 (ALI)过程中 ,内皮型一氧化氮合酶 (eNOS)及诱导型一氧化氮合酶 (iNOS)的表达及其在ALI发生中的作用。方法　SD大鼠 ,阻断肠系膜上动脉 (SMA) 60min ,根据不同再灌注时间随机分为A(60min)、B(12 0min)、C(2 40min)组。AC、BC、CC组分别为其对照组。Evans蓝法测定大鼠肺毛细血管通透性、逆转录 聚合酶链式反应 (RT PCR)法测定肺NOSmRNA表达、Western印迹法测定肺组织NOS表达 ,同时进行小肠组织学检查以评价肠损伤程度。结果　肺漏出量随着小肠再灌注时间延长而增加 ,A/AC组 :2 2 9.82± 18.13 /198.0 0± 2 2 .17;B/BC组 :2 74.12± 2 5 .40 /178.48± 2 0 .3 7;C/CC组 :2 69.87±2 0 .93 /195 .68± 10 .99。A与B组间比较差异有显著性。组织学检查 :小肠损伤在A组、B组及C组三组间差异有显著性。肺组织iNOS表达随再灌注时间延长而逐渐增加 ,其中A、C组比较差异有显著性 ,肺组织eNOS表达各组间差异无显著性。结论　肠道缺血 /再灌注损伤 :(1)导致肺毛细血管通透性改变及微血管漏出增加 ;(2 )引起肺内iNOS表达增高 ,且与小肠再灌注时间成正比 ,与肺血管漏出成正比。提示iNOS在肠缺血 /再灌注导致的肺损伤过程中可能起重要作用     

The effect of colchicine and low-dose methotrexate on intestinal ischemia/reperfusion injury in an experimental model

Aim

Intestinal ischemia/reperfusion (I/R) injury is a serious clinical condition. Colchicine and low-dose methotrexate have anti-inflammatory features. An experimental model was conducted to investigate the effect of colchicine and methotrexate on intestinal I/R injury.

Methods

Twenty-four rats were included. Only laparotomy was done in control group (CG, n = 6). In experimental groups, superior mesenteric artery was occluded. After 1 h ischemia, reperfusion (1 h) was started by de-occlusion. 30 min before reperfusion, saline in sham group (SG, n:6), colchicine (1 mg/kg) in colchicine group (CNG, n:6), and methotrexate (0.1 mg/kg) in methotrexate group (MTXG, n:6) were infused intraperitoneally. Small intestines were harvested for evaluation of intestinal mucosal injury (Chiu score) and oxidative stress markers (nitric oxide: NO, malondialdehyde: MDA, superoxide dismutase: SOD).

Results

Biochemically, MDA levels were significantly low in CG compared to SG, CNG, and MTXG (p < 0.05). NO levels were significantly low and SOD levels were significantly high in CG compared to MTXG (p < 0.05). Histopathologically, Chiu score was significantly low in CG compared to SG, CNG, and MTXG (p < 0.05), and significantly high in MTXG compared to SG and CNG (p < 0.05).

Conclusion

The present experimental model caused I/R injury in rat intestines. Contrary to literature, it was found that methotrexate worsens and colchicine does not attenuate intestinal I/R injury.     

Sotrastaurin, a protein kinase C inhibitor, ameliorates ischemia and reperfusion injury in rat orthotopic liver transplantation

Sotraustaurin (STN), a small molecule, targeted protein kinase C (PKC) inhibitor that prevents T-lymphocyte activation via a calcineurin-independent pathway, is currently being tested in Phase II renal and liver transplantation clinical trials. We have documented the key role of activated T cells in the inflammation cascade leading to liver ischemia/reperfusion injury (IRI). This study explores putative cytoprotective functions of STN in a clinically relevant rat model of hepatic cold ischemia followed by orthotopic liver transplantation (OLT). Livers from Sprague-Dawley rats were stored for 30 h at 4°C in UW solution, and then transplanted to syngeneic recipients. STN treatment of liver donors/recipients or recipients only prolonged OLT survival to >90% (vs. 40% in controls), decreased hepatocellular damage and improved histological features of IRI. STN treatment decreased activation of T cells, and diminished macrophage/neutrophil accumulation in OLTs. These beneficial effects were accompanied by diminished apoptosis, NF-κB/ERK signaling, depressed proapoptotic cleaved caspase-3, yet upregulated antiapoptotic Bcl-2/Bcl-xl and hepatic cell proliferation. In vitro, STN decreased PKCθ/IκBα activation and IL-2/IFN-γ production in ConA-stimulated spleen T cells, and diminished TNF-α/IL-1β in macrophage-T cell cocultures. This study documents positive effects of STN on liver IRI in OLT rat model that may translate as an additional benefit of STN in clinical liver transplantation.     

大鼠肺缺血再灌注损伤长期存活模型的建立

目的 建立一种简单、稳定的大鼠肺缺血再灌注损伤(LIRI)长期存活模型.方法 将84只健康SD大鼠随机分为2组:Ⅰ组为假手术组,Ⅱ组为肺缺血再灌注组(每组n=42只).两组分别于开胸后、缺血1 h后再灌注0、2、4h、1、3、7 d取肺组织行髓过氧化物酶(MPO)活性、肺湿干比(W/D ratio)检测和肺泡Ⅱ型细胞(ATⅡ)的电镜超微结构评价;取支气管肺泡灌洗液检测肺通透性指数(LPI).结果 手术成功率达100%.Ⅱ组与Ⅰ组比较,缺血再灌注后2、4 h、1 d的MPO、LPI、W/D比差异均有统计学意义(P<0.01),开胸后、再灌注后0 h、3、7 d两组比较差异无统计学意义(P>0.05).ATⅡ的超微结构显示,再灌注4 h后损伤最严重,再灌注1 d即出现明显的修复过程,再灌注7 d基本恢复正常结构水平.结论 本模型简单、可靠,LIRI后相关肺损伤指标和ATⅡ超微结构损伤变化特点吻合.     

Pretreatment with recombined human erythropoietin attenuates ischemia–reperfusion-induced lung injury in rats

Objective: Based on the findings that erythropoietin (EPO) has been proved to be a multiple functional cytokine to attenuate ischemia–reperfusion (I/R) injury in various organs such as brain, heart, and kidney in animals, this experiment was designed to evaluate the effect of pretreatment with recombined human erythropoietin (rhEPO) on I/R-induced lung injury. Methods: Left lungs of rats underwent 90 min of ischemia and then were reperfused for up to 2 h. Animals were randomly divided into three experimental groups as sham group, I/R group, and rhEPO + I/R group (a single dose of rhEPO was injected intraperitoneally 3000 U/kg 24 h prior to operation). Lung injury was evaluated according to semi-quantitive analysis of microscopic changes, tissue polymorphonuclear neutrophils (PMNs) accumulation (myeloperoxidase (MPO) activity), and pulmonary microvascular permeability (Evan's blue dying method). Peripheral arterial and venous blood samples were obtained for blood–gas analysis after 5 min occlusion of right lung hilus at the end of reperfusion. The serum concentration of tumor necrosis factor (TNF)- was also measured by the method of enzyme-linked immunosorbent assay. Results: Histological injury scoring revealed significantly lessened lung alveolus edema and neutrophils infiltration in the rhEPO pretreated group compared with I/R group (p < 0.05). The rhEPO pretreated animals exhibited markedly decreased lung microvascular permeability (p < 0.05) and myeloperoxidase activity (p < 0.05). Blood–gas analysis demonstrated that the pretreated animals had significantly ameliorated pulmonary oxygenation function (p < 0.05). The serum concentration of tumor necrosis factor- in rhEPO pretreated group was markedly decreased compared with that of I/R group (p < 0.05). Conclusions: Pretreatment with rhEPO appears to attenuate I/R-induced lung injury. This function is partly related with the capacity that rhEPO inhibits the accumulation of polymorphonuclear neutrophils in lung tissue and decreases the systematic expression of tumor necrosis factor-.     

缺血后适应在兔急性肠系膜缺血再灌注损伤模型中的作用

目的 观察缺血后适应干预措施能否减轻兔急性肠系膜缺血再灌注损伤.方法 将雄性新西兰兔120只随机分为空白对照(Con)组(仅开腹显露SMA)、缺血再灌注(I/R)组[肠系上动脉(superior mesenteric artery,SMA)缺血30 min后持续灌注120 min]、缺血后适应1(IpostC1)组(SMA缺血30 min后行3个循环的灌注30 s/阻断30 s,再持续灌注117 min)、缺血后适应2(IpostC2)组(SMA缺血30 min后行3个循环的灌注60s/阻断60 s,再持续灌注114 min),每组30只.干预后采集各组兔处理后下腔静脉血及部分肠道组织标本,试剂盒测定血清及肠道组织内丙二醛(MDA)、髓过氧化酶(MPO)水平,HE染色,Chiu 6级评分法观察肠黏膜损伤情况. 结果 与对照组比较,I/R组及IpostC1组、IpostC2组血清及肠道组织中MDA、MPO水平明显增加(P＜0.01),肠黏膜损伤评分明显升高(P＜0.01).与I/R组相比,IpostC1组血清和肠道组织中MDA、MPO水平及肠黏膜损伤评分明显降低(P＜0.01),而IpostC2组血清和肠道组织中MDA、MPO水平及肠黏膜损伤评分无明显降低(P＞0.05).结论 缺血后适应可明显降低兔急性肠系膜缺血再灌注损伤后下腔静脉血和肠道组织中MDA、MPO水平及肠黏膜损伤.     

Renal ischemia/reperfusion against nephrectomy for induction of acute lung injury in rats

Purpose: Acute kidney injury (AKI) induces acute lung injury (ALI) through releasing injurious mediators or impairing clearance of systemic factors. To determine the links between AKI and ALI, pulmonary and blood variables were evaluated following induction of AKI via different experimental models of bilateral renal ischemia/reperfusion (BIR: renal ischemia with uremia), unilateral renal ischemia/reperfusion (UIR: renal ischemia without uremia), bilateral nephrectomy (BNX: uremia without renal ischemia), and unilateral nephrectomy (UNX: without uremia and renal ischemia).

Methods: Ninety male Sprague–Dawley rats were divided into six groups. Animals had 1-h bilateral or 2-h unilateral renal ischemia followed by 24-h reperfusion in the BIR and UIR groups, respectively, and 24-h period following bilateral or unilateral nephrectomy in the BNX and UNX groups, respectively. There were also sham and control groups with and without sham-operation, respectively.

Results: Plasma malondialdehyde and nitric oxide were elevated by BIR more than UIR, but not changed by UNX and BNX. UIR slightly increased plasma creatinine, whereas BIR and BNX largely increased plasma creatinine, urea, K^+?and osmolality and decreased arterial HCO₃^?, pH, and CO₂. UNX and UIR did not affect lung, but BIR and BNX induced ALI with equal capillary leak and macrophages infiltration. However, there were more prominent lung edema and vascular congestion following BNX and more severe neutrophils infiltration and P_aO₂/F_iO₂ reduction following BIR.

Conclusion: Acutely accumulated systemic mediators following renal failure in the absence of kidneys vary from those due to combined renal failure with ischemic-reperfused kidneys and consequently they induce ALI with distinct characteristics.     

依达拉奉对大鼠小肠缺血-再灌注所致肺损伤的保护作用

目的探讨依达拉奉对大鼠小肠缺血-再灌注所致肺损伤的保护作用。方法雄性SD大鼠18只,随机均分为假手术组(Sham组),缺血-再灌注组(IR组)和依达拉奉组(E组)。Sham组只分离肠系膜上动脉,不做其他处理;IR组分离肠系膜上动脉,从大鼠尾静脉注射与E组等量的生理盐水后,用无创动脉夹夹闭120min后移去动脉夹,再灌注120min;E组在缺血-再灌注前静脉注射依达拉奉6mg/kg。再灌注120min后采集标本。肺组织HE染色后病理学检测,采集腹主动脉血液检测大鼠血清中TNF-α和IL-6浓度,取肺组织检测髓过氧化物酶(MPO)活性和丙二醛(MDA)浓度。结果与Sham组比较,IR组肺泡上皮细胞广泛水肿、炎性细胞浸润、肺泡肺萎陷、肺毛细血管扩张出血;E组肺组织病理改变较IR组明显改善,肺泡炎性渗出减少;E组病理评分为(2.1±0.7)分,明显低于IR组的(5.7±1.1)分,IR组病理评分明显高于Sham组的(1.5±0.2)分(P0.01);血清中TNF-α和IL-6的浓度明显少于IR组,肺组织中MPO活性和MDA浓度明显低于IR组(P0.01)。结论依达拉奉能够明显改善小肠缺血-再灌注性肺损伤。     

氯胺酮对大鼠全肝缺血/再灌注后肺损伤的保护作用及机制

目的 观察10 mg/kg氯胺酮对于大鼠全肝缺血/再灌注诱发的急性肺损伤保护作用及其机制.方法 30只9～10周龄雌性SD大鼠以区组随机法随机分为3组(每组10只),假手术组(Sham组),全肝缺血/再灌注组(IR组)以pringle's法阻断门静脉和肝动脉30 min后再灌注1h.全肝缺血/再灌注氯胺酮预处理组(Ket组),以10 mg/kg氯胺酮于全肝血流阻断前20 min经尾静脉注射预处理.测定各组肺组织干湿重比值(W/D比值);血清中天冬氨酸氨基转移酶(AST)、血清丙氨酸氨基转移酶(ALT)含量;逆转录/实时聚合酶链式反应( RT-PCR)法测定肺组织中血清肿瘤坏死因子-α(TNF-α)mRNA、细胞间黏附分子-1( ICAM-1 )mRNA含量;Western blot法测定肺组织中核因子-kb( NF-kJ )/P65含量;各组肺组织HE染色后病理评分.结果 血清AST、ALT含量:IR组[AST:(91±25)U/ml,ALT:(67.0±19.4) U/ml]和Ket组[AST:(85±12) U/ml,ALT:(51.3±9.9) U/ml]均高于Sham组[AST:(29±9) U/ml,ALT:(7.8±2.7) U/ml] (P＜0.05).血清TNF-α、ICAM-1含量:IR组[TNF.α:(23.1±4.8) μg/L,ICAM-1:(34±9)μg/L]和Ket组[TNF-α:(19.1+5.8)μg/L,ICAM-1:(41±7) μg/L]均高于Sham组[TNF-α:(8.7±2.4) μg/L,ICAM-1:(13±5)μg/L](P＜0.05).而Ket组和IR组之间无统计学差异(P＞0.05).W/D比值:IR组(6.9±1.7)和Ket组(5.1±1.1)高于Sham组(3.7±0.7)(P＜0.05),IR组高于Ket组(P＜0.05).肺组织中TNF-α mRNA、ICAM-1 mRNA和NF-kb/P65含量:IR组[TNF-α mRNA:(2.91±0.49)μg/L,ICAM-1 mRNA:(2.39±0.58) μg/L,NF-kb/P65:(1.97±0.17) μg/L]高于Sham组[TNF-αmRNA:(1.75±0.29) μg/L,ICAM-1 mRNA:( 1.63±0.33) μg/L,NF-kb/P65:(1.06±0.24) μg/L]和Ket组[TNF-α mRNA:(2.19±0.52) μg/L,ICAM-1 mRNA:(1.78±0.28)μg/L,NF-kb/P65:(1.33±0.30μg/L](P＜0.05).Sham组和Ket组之间无统计学差异(p＞0.05).肺组织病理评分:Sham组低于IR组和Ket组(P＜0.05),Ket组低于IR组(P＜0.05).相关性:TNF-α mRNA与NF-kb/P65正相关,R=0.849(P＜0.05),ICAM-1 mRNA与NF-kb/P65正相关,R=0.639(P＜0.05).结论 10 mg/kg氯胺酮20 min前预处理对于全肝缺血/再灌注肺损伤有保护作用.     

The protective effects of sildenafil in acute lung injury in a rat model of severe scald burn: A biochemical and histopathological study

Severe burn induces biochemical mediators such as reactive oxygen species that leads to lipid peroxidation which may have a key role in formation of acute lung injury (ALI). Sildenafil is a selective and potent inhibitor of cyclic guanosine monophosphate specific phosphodiesterase-5. Sildenafil preserves alveolar growth, angiogenesis, reduces inflammation and airway reactivity. The purpose of the present study was to evaluate the effects of different dosages of sildenafil in ALI due to severe scald burn in rats. Twenty-four rats were subjected to 30% total body surface area severe scald injury and were randomly divided into three equal groups as follow: control, 10 and 20 mg/kg sildenafil groups. Levels of malondialdehyde (MDA), activities of glutathione peroxidase (Gpx), catalase (Cat), total oxidative stress (TOS), and total antioxidative capacity (TAC) were measured in both tissues and serums. Oxidative stress index (OSI) was calculated. A semi-quantitative scoring system was used for the evaluation of histopatological findings. Sildenafil increased Gpx, Cat, TAC and decreased MDA, TOS and OSI. Sildenafil decreased inflammation scores in lungs. Our results reveal that sildenafil is protective against scald burn related ALI by decreasing oxidative stress and inflammation and the dosage of 10 mg/kg could be apparently better than 20 mg/kg.     

肾上腺髓质素对大鼠肺缺血再灌注损伤的保护作用

目的 观察肾上腺髓质素(ADM)在肺缺血再灌注损伤的保护作用.方法 三套管法建立大鼠左肺移植模型,分对照组和静脉ADM给药组(每分钟0.05μ/kg体重),分别进行髓过氧化物酶(MPO)活性测定、移植肺支气管肺泡灌洗液(BAL)中性粒细胞计数、缺血再灌注后血气分析以及移植肺组织湿/干(W/D)重最比测定.结果 再灌注4 h后,对照组的MPO活性(0.45±0.07)显著大于ADM给药组(0.24±0.06),差异有统计学意义(t=2.764,P<0.05).对照组左肺BAL中性粒细胞计数值为(152士23)×105,明显高于ADM给药组的BAL中性粒细胞计数值(87±12)×103,t=2.813,P<0.05.对照组移植肺组织湿/干(W/D)重量比为8.39±0.96,显著高于ADM给药组7.02±0.71(t=3.509,P<0.01).在灌注2 h时,对照组左肺静脉血氧分压为(177.62±23.12)mm Hg(1 mm Hg=0.133 kPa),显著低于ADM给药组(438.50±45.5)mm Hg(t=3.016,P<0.05);再灌注4 h时,对照组左肺静脉血氧分压为(141.75±19.32)him Hg,显著低于ADM给药组427.75±49.98(t=3.248,P<0.05.此外,对照组在再灌注4 h的左肺静脉血氧分压较再灌注2 h时明显降低(t=2.583,P<0.05);而ADM给药组在再灌注2h和4 h时的左肺静脉血氧分压却无显著变化(t=2.134,P>0.05).结论 ADM能够通过抑制移植肺缺血再灌注过程中炎性损伤的机制发挥其器官保护的功能.     

BQ-123对兔急性肺栓塞溶栓后缺血-再灌注损伤的保护作用

目的 观察内皮素-1(ET-1)受体拮抗剂BQ-123对兔急性肺栓塞溶栓后肺缺血-再灌注损伤的保护作用.方法 日本大耳白兔24只,雌雄不限,体质量(3.0±0.5) kg,随机分成4组(每组6只)即:假手术组(SHAM组)、栓塞组(PE组)、尿激酶组(UK组)、尿激酶+BQ-123组(UK+BQ组).各组分别于栓塞前、栓塞后0.5、2、4h监测记录肺动脉平均压并采静脉血检测血浆ET-1浓度,实验结束后测肺组织的湿/干比值(W/D比值)、超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量变化.结果 栓塞后0.5h,PE组、UK组、UK+ BQ组肺动脉平均压分别为(19.01±0.60) mm Hg(1 mm Hg=n133 kPa)、(20.14±0.85) mmHg、( 19.79±0.78) mmHg与SHAM组(18.92±0.63) mmHg比较肺动脉平均压升高(P＜0.05);UK+ BQ组(310.77±30.58) ng/L较UK组(371.18±35.43) ng/L在栓塞后4h血浆ET-1浓度下降(P＜0.05);UK+ BQ组与UK组比较,W/D比值、肺组织MDA含量降低,SOD活性升高(P＜0.05).结论 急性肺栓塞溶栓后早期出现了肺缺血再灌注损伤,ET-1可能是导致损伤的主要因素;急性肺栓塞溶栓前给予ET-1受体拮抗剂BQ-123对急性肺栓塞溶栓后缺血-再灌注损伤有一定的保护作用.     

Azithromycin reduces airway inflammation in a murine model of lung ischaemia reperfusion injury.

Clinical studies revealed that azithromycin reduces airway neutrophilia during chronic rejection after lung transplantation. Our aim was to investigate the possible effect of azithromycin on ischaemia-reperfusion injury. Azithromycin or water was administered to mice every other day during 2 weeks (n = 6/group). On the 14th day, the left lung was clamped to induce ischaemia (90 min). In two additional groups, animals underwent the same protocol, followed by 4 h of reperfusion. Two control groups were included with thoracotomy only. Inflammatory parameters and oxidative stress were measured in broncho-alveolar lavage of the left lung. Leukocytes, lymphocytes, neutrophils, 8-isoprostane and IL-1beta levels after ischaemia and reperfusion were significantly reduced in mice treated with azithromycin. There was a trend towards lower IL-6 and KC levels. A significant correlation was seen between 8-isoprostanes and neutrophils (Pearson r = 0.72; P = 0.0086), IL-6 (Pearson r = 0.84; P = 0.0006), KC (Pearson r = 0.88; P = 0.0002) and IL-1beta (Pearson r = 0.62; P = 0.0326). We conclude (i) that azithromycin reduces inflammation and oxidative stress in our IRI model, and (ii) that oxidative stress is correlated with the number of neutrophils and IL-6, KC and IL-1beta levels after ischaemia and reperfusion. Azithromycin should be further investigated as a novel drug to prevent lung ischaemia-reperfusion injury.     

异丙酚对肺缺血再灌注损伤大鼠肺上皮细胞凋亡的影响

目的拟通过观察肺上皮细胞凋亡的变化,探讨异丙酚减轻大鼠肺缺血再灌注损伤的作用机制。方法雄性SD大鼠136只,随机分为3组:假手术组(S组,n=24)、缺血再灌注组(I/R组,n=56)、异丙酚组(P组,n=56)。I/R组、P组制备大鼠肺原位热缺血模型,缺血1h。P组于缺血前30min静脉输注异丙酚20mg·kg~(-1)·h~(-1)至再灌注4h。S组除不作缺血处理外,其余处理与I/R组相同。分别于再灌注0.5、1、2、4h随机处死大鼠(S组每个时点处死6只,I/R组、P组每个时点分别处死14只大鼠),每组每个时点的一半大鼠用于测定支气管肺泡灌洗液(BALF)中中性粒细胞百分比、蛋白浓度,另外一半大鼠用于测定肺组织丙二醛(MDA)含量、湿,干重比(W/D)及肺上皮细胞凋亡指数(TUNEL法),并在光镜下观察肺组织的病理学改变;I/R组、P组肺上皮细胞凋亡指数与W/D进行直线相关分析。结果与S组相比,I/R组和P组再灌注各时点BALF中中性粒细胞百分比、蛋白浓度及肺组织MDA含量、W/D、肺上皮细胞凋亡指数均增加(P<0.05或0.01);与I/R组比较,P组上述指标均降低(P<0.05或0.01),肺组织病理学损伤减轻;I/R组、P组肺上皮细胞凋亡指数与W/D之间的相关系数分别为0.784、0.830(P<0.01)。结论异丙酚抑制肺上皮细胞凋亡可能是减轻大鼠肺缺血再灌注损伤的机制之一。