Lipopolysaccharide-induced lung injury in mice. I. Concomitant evaluation of inflammatory cells and haemorrhagic lung damage
Lipopolysaccharide-induced lung injury in mice. I. Concomitant evaluation of inflammatory cells and haemorrhagic lung damage
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DOI：
10.1006/pupt.2000.0231
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发表时间：
2000-01-01
影响因子：
3.2
通讯作者：
Caselli, GF
中科院分区：
文献类型：
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作者：
Asti, C;Ruggieri, V;Caselli, GF
气管内滴注脂多糖(LPS)可诱导炎症反应，其特征是中性粒细胞(PMN)渗入细胞外基质，并释放在肺损伤中起重要作用的介质。在目前的研究中，我们开发了一种小鼠模型，该模型允许同一动物的炎症反应和出血组织损伤之间的相关性。特别是，通过三个参数的分析来评估炎症反应和组织损伤的不同步骤：实质中反映PMN聚集到肺内的髓过氧化物酶(MPO)活性，反映其渗出的支气管肺泡灌洗液(BALF)中的炎细胞计数，以及BALF中总血红蛋白的测定，BALF中的总血红蛋白是PRNS脱颗粒所致出血组织损伤的标志。在我们的实验条件下，气管内注射10mU g/只内毒素可在内毒素刺激后4h(131%)和6h(147%)引起肺中MPO活性的增加。肺泡灌洗液中中性粒细胞数在注射后12~24 h显著升高，至24 h仍呈时间依赖性出血性肺损伤(4h：+38%；6 h：+23%；12 h：+44%；24 h：+129%)。肺损伤也进行了组织病理学评估。激发后24小时，内毒素组小鼠肺泡弥漫性出血，肺泡间质和肺泡内中性粒细胞聚集。该模型的药理学特征是在炎性级联反应的不同阶段给予抗炎药物进行预处理。结果表明：(1)倍他米松(1，3，11，30 mg/kg，po)呈剂量依赖性地减少肺组织中MPO活性和炎性细胞数，同时减少肺损伤；b)肿瘤坏死因子α产生抑制剂己酮可可碱(200 mg/kg，ip)抑制中性粒细胞渗出和肺出血，但不能降低肺组织中MPO活性；c)抗弹性蛋白酶化合物L-680,833(30 mg/kg，po)仅显著减轻出血性肺损伤；D)消炎痛是一种非类固醇抗炎药(5毫克/公斤，口服)，对所考虑的任何参数没有任何影响。总之，我们的活体小鼠模型是最近描述的ARDS(成人呼吸窘迫综合征)动物模型的实用替代方案，它允许解剖和表征PMN渗透的不同步骤，同时还可以研究它们的激活所造成的损害。(C)2000年学术出版社。
Intratracheal instillation of lipopolysaccharide (LPS) induces an inflammatory response characterized by infiltration of polymorphonoclear neutrophils (PMNs) into the extracellular matrix and by the release of mediators that play a fundamental role in lung damage. In the present study, we developed a mouse model which allows correlation of the inflammatory response and haemorrhagic tissue injury in the same animal. In particular, the different steps of the inflammatory response and tissue damage were evaluated by the analysis of three parameters: myeloperoxidase (MPO) activity in the parenchyma, reflecting PMNs accumulation into the lung, inflammatory cells count in the bronchoalveolar lavage fluid (BALF), reflecting their extravasation, and total haemoglobin estimation in BALF, a marker of haemorrhagic tissue damage consequent to PRNs degranulation.In our experimental conditions, intra-tracheal administration of 10 mu g/mouse of LPS evoked an increase of MPO activity in the lung at 4 h (131%) and 6 h (147%) from endotoxin challenge. A significant increase of PMNs in the BALF was noticed at these times with a plateau between the 12nd and 24th h. PMN accumulation produced a time-dependent haemorrhagic lung damage until 24 h after LPS injection (4 h: + 38%; 6 h: + 23%; 12 h: + 44%; 24 h: + 129% increase of haemoglobin concentration in the BALF vs. control). Lung injury was also assessed histopathologically. Twenty-four hours after the challenge, diffuse alveolar haemorrhage, as well as PMN recruitment in the interstitium and alveolus were observed in the LPS group.This model was pharmacologically characterized by pretreatment of LPS-treated mice with antiinflammatory drugs acting on different steps of the 'inflammatory cascade'. We demonstrated that: a) betamethasone (1, 3, Ill, 30 mg/kg po) reduced in a dose-dependent manner the MPO activity, the number of inflammatory cells and, at the same time, lung injury; b) pentoxifylline, a TNF alpha production inhibitor (200mg/kg ip), inhibited PMN extravasation and lung haemorrhage but it was not able to reduce MPO activity in the lung; c) L-680,833, an anti-elastase compound (30 mg/kg po), decreased significantly only the haemorrhagic lung damage; d) indomethacin, a non steroidal antiinflammatory drug (5 mg/kg po), did not show any effect on any of the parameters considered. In conclusion, our in vivo mouse model is a practical alternative to animal models of ARDS (Adult Respiratory Distress Syndrome) recently described and it permits to dissect and to characterize the different steps of PMNs infiltration and, at the same time, the damage caused by their activation. (C) 2000 Academic Press.