【作者】 李伟；

【导师】 唐文杰；

【作者基本信息】 南京大学 ， 急诊医学， 2011， 硕士

【摘要】 目的计算百草枯(paraquat, PQ)对小鼠急性肺损伤作用的半数致死量,建立可靠的急性肺损伤模型,探讨毗啡尼酮(pirfenidone, PD)对百草枯中毒导致ICR小鼠急性肺损伤(acute lung injury, ALI)的保护机制。方法选取80只ICR小鼠,随机分为8组,给小鼠腹腔注射不同剂量的百草枯溶液,记录小鼠3天及7天内不同时间点的死亡个数,计算其半数致死量；另选144只ICR小鼠分为空白对照组、中毒组、PD高剂量治疗组和PD低剂量治疗组。小鼠一次性腹腔注射30mg/kg PQ溶液以制作急性肺损伤模型,染毒后立即分别予PD30mg/kg、70mg/kg每日相同时间点灌胃1次,连续3天。于2h、6h、12h、24h、48h、72h时间点取小鼠肺组织匀浆检测NF-κB、TNF-α、IL-1β含量并分别观察各时间段的小鼠肺组织病理变化。结果ICR小鼠PQ中毒3日内的半数致死量为34.225mg/kg,7日内半数致死量为30.009mg/kg;与空白对照组相比,小鼠中毒组NF-κB、TNF-αIL-1β各时间点显著升高,持续至第3日仍未见明显下降；与中毒组相比,PD治疗组NF-κB亦升高但是24h、48h时低于中毒组,其中低剂量治疗组升高幅度小于高剂量组,但两者相比没有统计学差异(P>0.05)；病理检查可见小鼠PQ中毒肺泡腔有广泛的红细胞和浆液渗出,肺间质大量炎性细胞浸润以及肺泡间隔断裂,肺大疱形成；PD治疗组血管充血减轻,肺泡中炎性细胞和浆液渗出减少,肺大疱少见。结论小鼠百草枯中毒所致急性肺损伤可能和NF-κB、TNF-α、IL-1β的激活有关,吡啡尼酮对PQ中毒所致ICR小鼠ALI有治疗作用,其原理可能为抑制ALI时NF-κB、TNF-α、IL-1β的激活,从而减轻肺组织的炎症反应。更多还原

【Abstract】 Background Paraquat (PQ) is a widely used heterocyclic herbicide due to its effective weed destroying and better soil decomposition. Numerous fatalities have been caused by PQ intoxication through accidental or voluntary ingestion. The pathological mechanism of PQ poisoning is unclear yet. Some studies show that it may be associated with the release of perxiode and inflammatory mediators, activation of nitric oxide synthase system and DNA damage, etc. The alveolar epithelial cells can uptake PQ actively during the early times of poisoning, soon PQ is mainly accumulated in lungs and arose acute lung injury (ALI), and patients finally die in hypoxemia caused by multiple organ dysfunction (MODS) and lung fibrosis. Currently there is no effective treatment for PQ poisoning, to investigate the poisoning mechanism and effective treatment is a hot topic in emergency medicine and critical care medicine.Pirfenidone is a small molecule drugs while many researches show it is effective to acute lung injury and lung fibrosis, the effect may even better than the cortex of steroid hormones, This paper is to evaluate the protect effects and mechnism of pirfenidone through NF-κB、TNF-α、IL-1βin paraquat induced acute lung injury.Objective To establish a model of paraquat induced Acute lung injury in ICR mice, and observe the effects of pirfenidone on ALI treatment and its effects on inflammatory mediators NF-κB, TNF-a and IL-1β, to investigate the protective mechanism of pirfenidone on paraquat induced acute lung injury.Methods 80 ICR mice were randomly divided into 8 groups and treated with intraperitoneal injection of paraquat at the dosage of 10mg/kg to 60mg/kg, deaths of different time points were recorded during 3 days and 7 days, then LD50 of ICR mice were calculated by statistical software. Then 144 ICR mice weighting 23-27g were randomly divided into four groups:controlled group, poisoned group, high dose pirfenidone(70mg/kg) treated group and low dose pirfenidone(30mg/kg) treated group. Mice were random killed at 2nd,6th,12th,24th,48th and 72th hours after exposure to PQ, lung pathological changes were observed, NF-κB, IL-1βand TNF-a were asessed by ELISA.Results The LD50 of paraquat intoxication of 3 and 7 days were34.225mg/kg and 30.009mg/kg, Compare with the control group, NF-κB, TNF-a and IL-1βof poisoned group were greatly increased in the first 48h,and lasted until the following 24h;compare with poisoned group, The NF-κB, IL-1βand TNF-a activity of the PD treated group decreased but higher than the controlled group, Pathologic examination shows a wide range of red blood cells and serous effusion, pulmonary interstitial inflammatory cell infiltration, and alveolar septum fracture, but less vascular congestion and alveolar inflammatory cells and serous leakage reduction in the PD treated group. Conclusion Paraquat can induce a typical pathological change of ALI in ICR mice, NF-κB, TNF-a and IL-1βplay a important role in PQ induced lung injury, the therapeutic effect of PD may related to inhibit the expresstion of NF-κB、TNF-αand IL-1β, then reduce the inflammation in lung tissue.更多还原