Reduction in intestinal leukocyte adherence in rat experimental endotoxemia by treatment with the 21-aminosteroid U-74389G

OBJECTIVES: To investigate leukocyte adherence in intestinal venules in experimental endotoxemia after treatment with the 21-aminosteroid U-74389G. DESIGN AND SETTING: Prospective, randomized, controlled animal study in an experimental laboratory. SUBJECTS: Twenty-one male Wistar rats weighing 190 +/- 40 g. INTERVENTIONS: The rats were divided equally into three groups: (a) control group, (b) endotoxemia (5 mg/kg lipopolysacharide from Escherichia coli O55:B5), and (c) endotoxemia and U-74389G administration 30 min before (3 mg/kg) and 60 min after endotoxin challenge (1.5 mg/ kg). MEASUREMENTS AND MAIN RESULTS: The distal small intestine of the animals was examined using intravital fluorescence videomicroscopy 2 h after endotoxin challenge. Leukocytes were stained in vivo by means of rhodamine 6G. In the endotoxemic animals we observed a fourfold increase in the count of firmly adherent leukocytes in submucosal post-capillary and collecting venules. Treatment with the 21-aminosteroid U-74389G significantly attenuated the count of sticking leukocytes in the collecting venules (control, 61 +/- 10 cells/mm2; lipopolysaccharide, 237 +/- 42 cells/mm2; U-74389G 125 +/- 9 cells/mm2; p < 0.05). In these venules leukocyte rolling behavior was comparable to that in the control group without endotoxin challenge. CONCLUSIONS: Administration of U-74389G, which has radical scavenging properties, attenuates leukocyte adherence in selected populations of intestinal venules which is found increased during endotoxemia. Thus, 21-aminosteroids may have an impact in the treatment of endotoxin-induced intestinal injury.     

Inhibition of tumor necrosis factor-alpha release in rat experimental endotoxemia by treatment with the 21-aminosteroid U-74389G.

OBJECTIVE: To determine the effect of the 21-aminosteroid U-74389G on tumor necrosis factor (TNF)-alpha release in experimental endotoxemia. DESIGN: Prospective, randomized, controlled animal study. SETTING: Experimental laboratory. SUBJECTS: Twenty-one male Wistar rats weighing 190+/-40 g. INTERVENTIONS: The rats were divided equally into 3 groups: a) control; b) endotoxemia (5 mg/kg lipopolysaccharide [LPS] from Escherichia coli 055:B5); and c) endotoxemia and U-74389G administration 30 mins before (3 mg/kg) and 60 mins after (1.5 mg/kg) endotoxin challenge. MEASUREMENTS AND MAIN RESULTS: At 0, 120, and 240 mins, serum levels of TNF-alpha were measured using a specific rat TNF-alpha ELISA kit. U-74389G-treated endotoxemic animals showed significantly reduced TNF-alpha release 120 mins after endotoxin challenge (control, 2.5+/-2.1 pg/mL; LPS, 4041+/-871 pg/mL; U-74389G, 1627+/-474 pg/mL [p < .05]). Two hundred forty minutes after LPS administration, TNF-alpha levels decreased, whereas values in the untreated LPS group remained twice as high as those in the U-74389G group (LPS, 863+/-182 pg/mL; U-74389G, 369+/-54 pg/mL [p < .05]). CONCLUSIONS: The study demonstrated that administration of U-74389G, which has radical-scavenging and membrane-stabilizing properties, decreased TNF-alpha release during endotoxemia. Thus, 21-aminosteroids may lend themselves to evaluation in the treatment of septic states.     

Anti-inflammatory effects of U74389F in a rat model of intestinal ischemia/reperfusion injury.

OBJECTIVE: To investigate the role of eicosanoid generation and neutrophilic infiltration in the protective effects of U74389F against ischemia/reperfusion injury in the small intestines of rats. DESIGN: Prospective, randomized, controlled study. SETTING: University research laboratory. SUBJECTS: Adult, male Sprague-Dawley rats weighing between 200 and 300 g. INTERVENTIONS: Groups (5-8) of rats treated with U74389F or vehicle were subjected to a sham operation and 30 mins of ischemia by occlusion of the superior mesenteric artery or 30 mins of ischemia followed by 60 or 120 mins of reperfusion. U74389F (2.5 mg/kg i.v.) or vehicle (citrate buffer) were slowly injected 2 mins before ischemia. MEASUREMENTS AND MAIN RESULTS: Ischemia significantly (p < .05) increased mucosal injury (0 [normal] to 5) in both U74389F and untreated rats. In contrast, U74389F significantly (p < .05) attenuated the severity of injury after reperfusion. In vehicle-treated rats, ischemia/reperfusion significantly reduced villus height in both U74389F and untreated groups. However, the surface epithelial layer was intact in the U74389F but not in the vehicle-treated group. In addition, compared with the vehicle-treated group, U74389F significantly reduced neutrophil infiltration and prevented the increase in leukotriene B4 and prostaglandin E2 in response to ischemia and reperfusion. CONCLUSIONS: This study demonstrates that the mechanism of U74389F against mesenteric ischemia/reperfusion includes a delay and reduction of neutrophilic infiltrate, an inhibition of leukotriene B4 production, and a facilitation of mucosal restitution.     

新型21-氨基类固醇U-74389G对脑外伤后脑保护作用的机制

目的探讨21-氨基类固醇U-74389G对脑外伤治疗作用的机制。方法用丙二醛(MDA)和一氧化氮(NO)试剂盒测定不同组别大鼠中度脑损伤后脑组织及血清中MDA和NO的含量。结果对照组脑组织及血清中MDA和NO含量较假外伤组增加,而治疗组比对照组下降。结论U-74389G能抑制脑损伤后氧自由基引致的脂质过氧化反应和NO的合成。     

Lazaroid pretreatment preserves gas exchange in endotoxin-treated dogs

: The lazaroids are a new class of potent free-radical scavengers. We tested whether U-74389G, a lazaroid, could attenuate some of the adverse cardiopulmonary effects of sepsis.

: Dogs were randomized to receive either 10 mg/kg U-74389G (n = 10), or a saline control (n = 11). After baseline measurements of hemodynamics and gas exchange, they were then randomized to receive either 0.2 mg/kg endotoxin or a saline infusion. Measurements of hemodynamics and gas exchange were repeated. The study was concluded 70 minutes after endotoxin infusion and the lungs were then removed for histologic evaluation.

: In endotoxin-treated control animals, P0₂ decreased (278 ± 123 mm Hg to 67 ± 13 mm Hg, P < .05) and intrapulmonary shunt increased (12.9% ± 1.1% to 28.2% ± 11.4%, P < .05) after endotoxin. Pretreatment with U-74389G attenuated the decrease in PO₂ (476 ± 61 mm Hg to 226 ± 143) and the increase in intrapulmonary shunt (12.6% ± 6.1% to 14.3% ± 6.8%) observed after endotoxin. The extent of lung injury and systemic hemodynamics were similar between control or U-74389G-treated dogs.

: A free-radical-scavenger can attenuate the gas exchange defect commonly associated with endotoxin but it does not improve the derangement of systemic hemodynamics.     

Fructose-1,6-diphosphate attenuates acute lung injury induced by ischemia-reperfusion in rats

OBJECTIVE: To determine whether fructose-1,6-diphosphate (FDP) pretreatment can attenuate acute lung injury induced by ischemia-reperfusion in our isolated lung model in rats. DESIGN: Randomized, controlled study. SETTING: Animal care facility procedure room. SUBJECTS: Twenty-four adult male Sprague-Dawley rats each weighing 250-350 g. INTERVENTIONS: Typical acute lung injury in rats was induced successfully by 10 mins of hypoxia followed by 75 mins of ischemia and 50 mins of reperfusion. Ischemia-reperfusion significantly increased microvascular permeability as measured by the capillary filtration coefficient, lung weight gain, lung weight to body weight ratio, pulmonary arterial pressure, and protein concentration of bronchoalveolar lav-age fluid. MEASUREMENTS AND MAIN RESULTS: Pretreatment with FDP significantly attenuated the acute lung injury induced by ischemia-reperfusion as shown by a significant decrease in all of the assessed variables (p <.05 p <.001). The protective effect of FDP was nearly undetectable when promazine (an ecto-adenosine 5-triphosphatase inhibitor) was added before FDP pretreatment. CONCLUSIONS: Pretreatment with FDP significantly ameliorates acute lung injury induced by ischemia-reperfusion in rats.     

Pulmonary edema induced by phorbol myristate acetate is attenuated by compounds that increase intracellular cAMP

We have investigated the effect of terbutaline, aminophylline and dibutyryl cyclic AMP (DBcAMP) on phorbol myristate acetate (PMA)-induced acute lung injury in isolated, blood-perfused rabbit lungs. Pulmonary arterial pressure and lung weight were measured for 30 min after a bolus injection of PMA (10 μg/kg). In the group exposed to PMA alone, the mean pulmonary arterial pressure (PAP) increased from 16.33±1.28 to 77.30±6.40 mmHg (P<0.001), and lung weight increased by 70.69±10.94 g during the 30 min after PMA challenge (P<0.001). Pretreatment with terbutaline, aminophylline or DBcAMP prevented the increases in both PAP and lung weight (P<0.001). Each of the three drugs also prevented the increase in pulmonary vascular permeability induced by PMA: terbutaline, aminophylline, and DBcAMP all significantly reduced the pulmonary capillary filtration coefficient (K_fc) as well as the albumin concentration in the lung, lavage fluid after PMA exposure. Post-treatment with terbutaline 5 min after PMA administration also had a protective effect. The mechanisms responsible for these protective effects may all involve an increase in intracellular cAMP, since all three drugs increase cAMP in the lung (though by different mechanisms). Our data further indicate that the inhibition of tumor necrosis factor production may likewise play an important role in the protective effect exerted by these drugs.     

A lazaroid mitigates postresuscitation myocardial dysfunction

OBJECTIVE: Lazaroids, a series of 21-aminosteroids, reduce free radical mediated injury after ischemia and reperfusion. We hypothesized that the lazaroid U-74389G would minimize postresuscitation myocardial dysfunction and thereby improve neurologically meaningful survival in a rodent model after resuscitation from 8 mins of ventricular fibrillation. DESIGN: Randomized, controlled laboratory study. SETTING: University-affiliated research institute. SUBJECTS: Sprague-Dawley rats. INTERVENTIONS: Ventricular fibrillation was electrically induced in ten anesthetized Sprague-Dawley rats. The lazaroid agent U-74389G in a dose of 1 mg.kg-1 or its vehicle serving as a placebo was injected into the right atrium after 7 mins of untreated ventricular fibrillation. One minute after injection of the compound, precordial compression was begun together with mechanical ventilation and continued for 6 mins before attempted electrical defibrillation. MEASUREMENTS AND MAIN RESULTS: All animals were successfully resuscitated. Postresuscitation cardiac index, left ventricular end-diastolic pressure, the rate of left ventricular pressure increase measured at a left ventricular pressure of 40 mm Hg, and the maximum rate of left ventricular pressure decline were significantly less impaired in lazaroid-treated animals. This contrasted with control animals, which had significantly greater myocardial impairment, greater neurologic deficit, and lesser duration of survival. CONCLUSIONS: The lazaroid compound U-74389G, administered during cardiac arrest, mitigated postresuscitation myocardial dysfunction and improved survival.     

The acute effect of the antioxidant drug “U-74389G” on red blood cells levels during hypoxia reoxygenation injury in rats

ObjectiveTo examine the effect of the antioxidant drug “U-74389G”, on rat model and particularly in a hypoxia reoxygenation (HR) protocol. The beneficial effect or non-effectiveness of that molecule was studied hematologically using mean red blood cells levels.Methods40 rats of mean weight 231.875 g were used in the study. Red blood cells levels were measured 60 min after reoxygenation (groups A and C) and 120 min after reoxygenation (groups B and D) with administration of the drug U-74389G only in groups C and D.ResultsU-74389G administration non-significantly increased the red blood cells level by (0.64±0.32)% (P=0.810 6). Reoxygenation time also non-significantly increased the red blood cells level by (4.63±2.36)% (P=0.068 0). However, U-74389G administration and reoxygenation time together non-significantly increased the red blood cells level by (1.05±0.53)% (P=0.491 1).ConclusionsResults of this study show that U-74389G administration, reoxygenation time and their interaction non significantly increased the red blood cells levels within 2 hours' time interval.     

沐舒坦对吸入性肺损伤大鼠的肺保护作用

目的评价预先使用药物沐舒坦对稀盐酸吸入性肺损伤是否具有保护作用,为临床治疗提供理论依据。方法30只健康SD大鼠随机分成3组:A组为生理盐水吸入组;B组为稀盐酸吸入组;C组为稀盐酸吸入加沐舒坦处理组。C组预先以50mg/kg沐舒坦腹腔注射,每日1次,连续3d;A、B两组则以腹腔注射等体积生理盐水代替。第3d腹腔注射沐舒坦或生理盐水30min后,A组以1.2ml/kg(pH5.3)的生理盐水经气管内注入造成非盐酸吸入肺损伤作为对照;B、C组则以1.2ml/kg(pH1.25)的盐酸加生理盐水混合液经气管内注入制备盐酸吸入性肺损伤模型。观察盐酸注入5h后大鼠动脉血气、肺湿/干重比(W/D)以及光镜下肺组织病理改变及肺损伤评分。结果1B、C组动脉血氧分压(PaO2)在盐酸吸入5h时比A组明显降低,B组又低于C组,组间比较差异均有显著性(P均<0.01);但pH和动脉血二氧化碳分压(PaCO2)在3组间差异无显著性(P>0.05)。23组W/D由低到高依次为A组、C组和B组,组间比较差异均有显著性(P均<0.01)。3光镜下组织病理学观察发现,B组肺损伤最为严重,而C组损伤比B组要轻;肺损伤程度评分A组最低,C组较B组低,3组间比较差异有显著性(P<0.05或P<0.01)。结论沐舒坦能减轻稀盐酸吸入所引起弥漫性肺损伤。     

Surfactant treatment impairs gas exchange in a canine model of acute lung injury

The effectiveness of surfactant (SURF) treatment in acute lung injury in the adult is controversial. In this study, we tested the effectiveness of early surfactant treatment in a commonly used animal model of acute lung injury, phorbol-myristate acetate (PMA), to see if it would attenuate the progression of lung injury. We measured the effect on lung compliance and whether positive end-expiratory pressure (PEEP) (10 cm H2O) during SURF administration had a synergistic effect. METHODS: Four groups of anesthetized dogs were studied: a) normals; b) PMA injury only; c) PMA injury + SURF; and d) PMA + SURF + PEEP. Lung injury was induced with 25-30 microg/kg of PMA. Responses were measured over 7 hrs. Surfactant was administered in the form of Survanta, 4 x 25 mg/kg doses via tracheal instillation 2.5 hrs after PMA. For the group receiving PEEP, 10 cm H2O PEEP was begun 1.5 hrs after PMA, 1 hr before SURF. Postmortem, the left lung was excised and inflated three times to total lung capacity (volume at 30 cm H2O) and expiratory compliance was measured with 25-100 mL volume increments. The trachea was then clamped and trapped volume was determined by water displacement. RESULTS: PMA-induced lung injury significantly reduced expiratory compliance and total lung capacity (p < .05 from normal). Wet/dry lung weights did not differ between groups. SURF without PEEP further decreased lung compliance as compared with PMA only. CONCLUSIONS: SURF administration after PMA injury causes marked reductions in lung compliance when no PEEP is coadministered. However, the loss of static expiratory lung compliance appears partly ameliorated by application of PEEP + SURF. Given that tracheal instillation of SURF is known to acutely elevate lung impedance in the first few hours after administration, coadministration of PEEP appears to be critically important in counteracting these early effects of surfactant instillation on the lung.     

血管活性肠肽对内毒素性休克大鼠肺损伤的保护作用

目的 观察血管活性肠肽(VIP)对内毒索性休克大鼠肺损伤的作用,并探讨其可能机制.方法 SD大鼠静脉注射内毒素(E Coil LPS O111B4)10 mg/kg制作内毒素休克模型.随机将30只大鼠分成对照组(生理盐水,n=10)、内毒素组(内毒素10 mg/kg,n=10)和VIP组(内毒素10mg/kg+VIP 5 nmol,n=10).注药6 h后留取标本,测定各组肺干/湿比(W/D值)、支气管灌洗液(BALF)蛋白浓度和中性粒细胞计数,酶联免疫吸附法(ELISA)测定血清及BALF的肿瘤坏死因子-α(TNF-α)、白介紊-1(IL-1)和IL-10水平,观察肺组织病理变化(光镜+电镜).结果 内毒素组肺W/D值、BALF蛋白浓度和中性粒细胞计数比为(4.75±0.31),(68±6)%,(260±72)mg/L,对照组和VIP组分别为(3.61±0.28),(15±9)%,(70±21)mg/L和(4.02±0.25),(44±8)%,(123±44)mg/L,差异具有统计学意义(P＜0.05).内毒索组血清和BLAF中的TNF-α、IL-1β、IL-10明显升高(P＜0.05),VIP组与内毒素组比较TNF-α、IL-1β明显降低(P＜0.05),但仍高于对照组,IL-10较内毒素组进一步升高.光镜和电镜下VIP组病变轻于内毒素组.结论 VIP可减轻大鼠内毒索休克肺损伤,其作用机制可能与调控炎症细胞因子的表达有关.     

低温对大鼠急性肺损伤肺脂质过氧化的影响

目的 :探讨 3 2 5℃～ 3 3℃低温对大鼠内毒素性急性肺损伤 (ALI)肺脂质过氧化的影响。方法 :采用大鼠腹腔注射内毒素 ,16h后再行气管内滴注内毒素的方法建立ALI模型。 2 4只雄性SD大鼠随机分为 3组 :正常对照组、内毒素组、低温组。ALI后 4h ,检测肺组织丙二醛 (MDA)含量和超氧化物歧化酶 (SOD)活性。结果 :3组各时间点MAP、CVP相比无统计学意义 ( P>0 0 5)。内毒素组大鼠肺组织MDA含量显著高于正常对照组 ,SOD活性显著下降 ( P <0 0 5)。低温组SOD活性显著高于内毒素组 ,MDA含量也显著下降 (P <0 0 5) ,但与对照组相比无统计学意义 (P >0 0 5)。结论 :低温可减轻大鼠内毒素性急性肺损伤肺组织脂质过氧化。     

Insulin attenuates endotoxin-induced acute lung injury in conscious rats

OBJECTIVES: To investigate the effects of insulin on the acute lung injury induced by lipopolysaccharide using a conscious rat model. DESIGN: Prospective, randomized, controlled animal study. SETTING: University research laboratory. SUBJECTS: A total of 190 adult male Sprague-Dawley rats weighing 250-300 g. INTERVENTIONS: Endotoxemia was induced by intravenous infusion of lipopolysaccharide. Lipopolysaccharide at various doses (0, 1, 5, 10, 20, and 30 mg/kg, n=10 for each dose) was administered intravenously in 20 mins. Insulin infusion at doses of 0.5, 1, and 5 microU/kg/min was given 5 mins before lipopolysaccharide administration. Plasma glucose was clamped at 90-110 mg/dL by infusion of 10-80% glucose solution. Insulin and glucose infusion (0.01 mL/min) was started 5 mins before lipopolysaccharide and continued for 120 mins. The rats received a total of 60, 120, and 600 microU/kg insulin as well as 0.12, 0.36, and 0.96 g of glucose in respective groups. The animals were then observed for 4 hrs. MEASUREMENTS AND MAIN RESULTS: The extent of acute lung injury was evaluated by lung weight/body weight ratio, lung weight gain, protein concentration in bronchoalveolar lavage, and exhaled nitric oxide. We also measured plasma nitrate/nitrite and methyl guanidine. In addition, histopathologic changes of the lung were examined. Lipopolysaccharide caused systemic hypotension and severe acute lung injury with increases in plasma nitrate/nitrite and methyl guanidine. Pretreatment with insulin infusion at doses of 0.5, 1, and 5 microU/kg/min mitigated or prevented systemic hypotension and the development of acute lung injury, depending on the dose. Insulin also attenuated the lipopolysaccharide-induced increases in nitrate/nitrite and methyl guanidine. CONCLUSIONS: Insulin is effective in reducing or preventing the lipopolysaccharide-induced increases in plasma nitrate/nitrite and methyl guanidine and the occurrence of acute lung injury.     

N-乙酰半胱氨酸对偏二甲基肼和四氧化二氮吸入性肺损伤的保护作用

目的观察N-乙酰半胱氨酸(NAC)对大剂量火箭液体推进剂偏二甲基肼(UDMH)和四氧化二氮(N2O4)吸入性急性肺损伤(ALI)的保护性作用.方法42只大鼠随机平均分为对照组、毒物暴露组(暴露组)和毒物暴露+NAC治疗组(NAC干预组).制模动物在静式染毒柜中染毒,UDMH和N2O4质量浓度分别为0.98 mg/L和0.19 mg/L,均染毒10 min.NAC干预组染毒后立即经尾静脉注射NAC150 mg/kg,3 h后再次补充50 mg/kg NAC腹腔注射;另两组均以等量生理盐水代替.各组动物均于实验后6 h测定肺组织湿/干质量比(W/D)、支气管肺泡灌洗液(BALF)蛋白含量和乳酸脱氢酶(LDH)活性、肺组织超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)和血浆丙二醛(MDA),并观察动物一般情况及组织病理学变化.结果与对照组相比,暴露组大鼠肺W/D、BALF中蛋白和LDH以及血浆MDA等均明显增加,而肺组织SOD、GSH-Px活性则明显降低;NAC干预组上述指标均有不同程度改善.暴露组大鼠有明显憋喘症状,病理学表现为明显的肺泡内渗出和肺间质水肿;而NAC干预组上述改变明显减轻.肺W/D与肺组织SOD和GSH-Px活性均呈显著负相关,相关系数r分别为-0.662和-0.707(P均＜0.01).结论NAC对大剂量UDMH和N2O4吸入性ALI有保护性治疗作用,其作用机制可能与其抗氧化和防治脂质过氧化损伤有关.     

Protective effect of a direct renin inhibitor in acute murine model of cardiotoxicity and nephrotoxicity

This study aimed to investigate the possible protective effects of aliskiren against doxorubicin (DXR)‐induced cardiorenal injury and to identify the mechanisms involved. Intraperitoneal administration of DXR (15 mg/kg, body weight, as a single dose) caused significant induction in the levels of angiotensin I, caspase‐3, lactate dehydrogenase (LDH), lipid peroxidation malondialdehyde (MDA), urea, and creatinine. Concomitant decline in the levels of albumin and total protein in plasma, reduction in reduced glutathione (GSH), and antiperoxidative enzyme superoxide dismutase (SOD) levels followed by ultrastructural alterations in the myocardial and renal tissues were also observed. Oral administration of aliskiren (100 mg/kg, for a period of 14 days) significantly prevented all these DXR‐induced adverse effects and maintained the rats near to normal status. However, telmisartan (10 mg/kg) pretreatment has shown slight protection in DXR‐induced renal injury as evidenced by broadening of podocyte foot process and narrowing of slit pore diameter. The results of aliskiren were compared with telmisartan which was used as reference in this study. These results suggested that aliskiren has protective effects against acute model of DXR‐induced cardiotoxicity and nephrotoxicity, implying that plasma renin activity plays a role in DXR‐induced cardio‐renal injury.     

维生素C对脂多糖急性肺损伤大鼠的保护作用

目的 观察维生素C对大鼠脂多糖性急性肺损伤的保护作用及其机制。方法 健康成年Sprague—Dawley（SD）大鼠24只,雌雄不拘,体重180—200g,随机分成三组：0．9％氯化钠注射液组（NS组）、脂多糖组（LPS组）和维生素C治疗组（VitC组）,每组8只大鼠。三组大鼠分别在脂多糖或0．9％氯化钠注射液注入后4h放血处死,测定肺组织丙二醛含量、髓过氧化物酶活性（myeloperoxiase,MPO）及肺湿干重比值（W／D）,留少许肺标本固定切片观察病理变化。结果 与NS组比较,LPS组肺组织MDA含量显著增加、MPO活性显著升高,W／D显著增加（t分别=0．01、6．54、6．19,P均〈0．05）;与LPS组比较,VitC组肺组织MDA含量减少、MPO活性明显降低、W／D显著下降（t分别=0．02、7．73、4．61,P均〈0．05）。LPS组肺组织病理切片可见明显急性肺损伤病理改变,维生素C治疗组显示损伤较轻。讨论 大剂量维生素C对脂多糖所致的大鼠急性肺损伤具有保护作用。     

蛋白酶抑制剂和激素对肺损伤保护作用的比较

目的 探讨并比较蛋白酶抑制剂和激素对内毒素性急性肺损伤的保护作用,为临床药物的选择提供依据.方法 新西兰大白兔32只,随机(随机数字法)分为对照组(C组)、内毒素组(L组)、乌司他丁组(U组)和地塞米松组(D组),每组8只.除C组外,其他组均经耳缘静脉给予内毒素(600μg/kg),U、D组在给予内毒素同时分别静脉注射乌司他丁(100000 U/kg)、地塞米松(5 mg/kg).4h后测定血清肿瘤坏死因子α(TNF-α)及一氧化氮(NO)水平,行动脉血气分析,取肺组织观察大体标本形态和光镜下的组织病理形态,测定肺组织湿/干质量比值(W/D)、髓过氧化物酶(MPO)活性、脂质过氧化产物丙二醛(MDA)及超氧化物歧化酶(SOD)活性.数据采用单因素方差分析(SNK-q检验),以P<0.05为差异有统计学意义.结果 光镜下见C组肺组织学正常,L组肺间质弥漫性出血、肺泡腔内可见大量粒细胞聚集、浸润,并可见弥漫性肺泡间隔增厚,而U,D组上述病理表现明显减轻.U,D组与L组相比较兔肺组织湿/干质量比[(5.02±0.11),(4.93 ±0.13)vs.(5.37±0.29)],MPO[(0.51±0.05),(0.54 ±0.07)vs.(0.82±0.09)],MDA[(0.82±0.05),(0.81±0.04)vs.(0.96±0.05)]以及血清NO水平[(296.2±11.7),(291.7±15.8)vs.(351.8±19.6)]和TNF-α[D组(2.021±0.122)vs.L组(4.999±0.139)]明显降低、SOD活性[(120.3±6.1),(122.6±3.5)vs.(105.1±8.5)]明显增强、动脉血气中pH[(7.30 ±0.23),(7.30±0.17)vs.(7.22±0.45)]和PaO_2[(101.9±6.8),(102.5±4.7)vs.(80.3±3.3)]明显升高,差异有统计学意义(P<0.05);而U组与D组上述指标相比较,差异无统计学意义(P>0.05);U,D组与L组相比较PaCO_2[(37.0±3.3),(37.6±3.0)vs.(34.8±2.3)],差异无统计学意义(P>0.05).结论 乌司他丁对内毒素性急性肺损伤的保护作用与地塞米松相当,在临床上可替代地塞米松以减少其副作用.     

Proteases and oxidants in experimental pulmonary inflammatory injury.

We have examined various biochemical parameters of pulmonary inflammation in experimental animals. Intrabronchial instillation of glucose oxidase-glucose (GO/G) to produce oxidants or formylated norleu-leu-phe (FNLP) or phorbol myristate acetate (PMA) as leukocytic stimuli induced severe acute pulmonary injury in New Zealand white rabbits. PMA also induced inflammation when administered intravenously. Each stimulus induced transudation of protein from the vascular space into the pulmonary tissues, and an influx of leukocytes during the 4-6 h period of the experiment. Pathophysiologic changes were measured by edema formation (transudation of 125I-bovine serum albumin), and histologic examination. Biochemical analysis was performed by measuring concentrations of potentially injurious agents in bronchoalveolar lavage (BAL) fluid. Increased acid protease and myeloperoxidase levels were found in the BAL fluid after administration of either of the stimuli. Evidence of oxidant generation in vivo was obtained in two different ways. In the first, specific activities for catalase were measured in the BAL fluid in the presence or absence of 3-amino, 1,2,4 triazole (AT), injected at intervals before obtaining BAL fluid. In the presence of AT, specific activities for catalase dropped to 0.22 after a double instillation of FNLP and to 0.15 in the presence of GO/G. In neutrophil-depleted FNLP animals, catalase was not greatly inhibited by AT (sp act 0.90). In the second, intracellular levels of total glutathione (GSH + GSSG) in whole lung tissue and alveolar macrophages decreased when stimuli of neutrophils were administered. Intrabronchially instilled PMA, e.g., caused a drop of glutathione in whole lung tissue from the control value of 2.3 mumol GSH equivalent/100 mg dry wt to 0.54 mumol GSH equivalent/100 mg dry wt at 4 h. Neutrophil depletion and superoxide dismutase protected from this effect. From these results, we conclude that O-2 or its metabolites can initiate severe pulmonary injury as shown by the effect of GO/G and that, during development of pulmonary injury, stimulated neutrophils generate oxidants and release proteolytic enzymes into the surrounding tissues.     

丙戊酸钠对脂多糖诱导大鼠急性肺损伤的保护作用

目的 研究丙戊酸钠(valproic acid,VPA)对脂多糖(lipopolysaccharide,LPS)诱导的大鼠急性肺损伤的影响.方法 实验地点在武汉协和医院中心实验室,通过股静脉注射LPS复制大鼠急性肺损伤模型,观察光镜下肺组织病理学改变、血清炎性因子和肺部炎性反应判定模型是否成功.依据干预药物的不同确定实验分组:股静脉给予5mL/kg生理盐水为对照组(NS组),股静脉给予LPS 10 mg/kg为模型组(LPS组),模型成功后股静脉给予VPA 300mg/kg治疗为治疗组(LPS+VPA组).注射LPS或NS后6 h处死动物,血气分析观察动脉血氧分压(PaO2)、肺泡气-动脉血氧分压差(A-aDO2)、乳酸(Lac),检测肺组织干湿重比(W/D),髓过氧化物酶(MPO)活性,肺泡灌洗液(BALF)中白蛋白质量浓度,用ELISA法检测6 h血清中TNF-α和IL-1β的含量,HE染色光镜下观察肺组织病理学变化.计量资料以均数±标准差(-x±s)表示,应用SPSS 13.0统计软件行单因素方差分析.结果 LPS组PaO2(mmHg)(81.50±3.24)较NS组(106.40±4.50)降低,A-aDO2(mmHg),Lac[(19.70±2.21),(3.63±0.22)]较NS组[(6.30±1.70),(1.21±0.19)]升高,W/D,MPO活性(μ/g),BALF中白蛋白质量浓度(pg/mL)分别为[(6.52±0.30),(7.25±0.49),(2.940±0.047)]较NS组[(4.38±0.17),(1.76±0.31),(0.099±0.077)]升高,血清中TNF-α和IL-1β的质量浓度(pg/ml)分别为(3325±284),(1950±222)较NS组(90±12),(50±11)显著升高,差异具有统计学意义(P＜0.05),LPS组肺组织出现病理学改变;与LPS组比较,LPS+VPA组上述指标除PaO2(mmHg)(94.50±4.38)上升外,其余指标均降至[(13.50±4.77),(2.13±1.02),(5.33±0.12),(4.38±0.42),(1.260±0.039),(2410±320),(1220±162)],差异具有统计学意义(P＜0.05),LPS+VPA组肺组织病理学改变明显减轻.结论 丙戊酸钠对脂多糖诱导的大鼠急性肺损伤有一定保护作用.

Abstract：

Objective To investigate the effects of valproic acid (VPA) on acute lung injury induced by Lipopolysaccharide in rats. Method The rat model of acute lung injury was made by intravenous injection of lipopolysaccharide (LPS). The pathological changes of lung were observed under light microscope and inflammatory cytokines in serum detected by using ELISA to judge whether the model was successfully done or not. All rats were divided into three groups as per the different intervention agents employed. Rats in control group were treated with intravenous injection of NS in dose of 5 ml/kg, rats in LPS group were exposed to LPS with dosage of 10 mg/kg and model rats in LPS + VPA group were treated with VPA in dose of 300 mg/kg. The rats were sacrificed 6 h after LPS or NS administration. The blood PaO2 ,A-aDO2 and blood lactic acid (Lac) were measured, the lungs were removed for observing the histopathological changes and determination of wet/dry lung weight (W/D) ratio and myeloperoxidase (MPO) activity as well as albumin concentration in broncho-alveolar lavage fluid (BALF) . Seurm was collected to determine the concentrations of tumor necrosis factor-a (TNF-α) and interleukin-1β( IL-1 β) by using LISA 6 h later. All data were presented in ((x)±s). One-way ANOVA was used for comparing differences between groups. Results Compared with acute lung injury group, the blood PaO2 (94. 50 ± 4.38 ) in rats of LPS + VPA group was higher, whereas A-aDO2 ( 13.50 ± 4.77 ) and blood lac( 2.13 ± 1. 02 ) in LPS + VPA group were lower. VPA significantly lowered W/D (5.33 ±0. 12) ratio and MPO activity (4.38 ±0. 42) in the lung. Albumin concentration ( 1. 260 ± 0. 039 ) in BALF, and the levels of TN F-α( 2 410 ±320 )and IL-1β( 1 220 ± 162 )in serum were lower in LPS + VPA group. The histological changes of lung injury were lessened by VPA. Conclusions Valproic acid has protective effects against lipopolysaccharide-induced acute lung injury in rats.