不同模式口鼻式吸烟诱导急性肺损伤的实验研究

Cigarette smoking in different manners induces acute lung injury in rats

目的：研究不同抽吸模式的口鼻式吸烟方式诱导大鼠急性肺损伤的效应。方法：市售焦油含量分别为1、5、11mg的卷烟按照加拿大深度抽吸模式（深度抽吸）及11mg焦油含量的卷烟按国际标准抽吸模式（国标抽吸）抽吸．并以空气为载气将卷烟烟雾载入大鼠口鼻暴露塔中；大鼠固定于固定器中，仅口鼻暴露于主流烟气中，吸烟28d后处死大鼠进行左肺肺泡灌洗，肺泡灌洗液用于炎症细胞计数和分类以及ELISA检测炎症因子IL-1β和TNF-α水平；右肺下叶进行组织病理学观察；右肺上叶冻存并用于髓过氧化物酶（MPO）、超氧化物歧化酶（SOD）活性及还原型谷胱甘肽（GSH）、活性氧和丙二醛含量检测。结果：同等抽吸模式下，大鼠吸入卷烟的烟气质量浓度与样品卷烟盒标记的焦油等有害物质含量成正比。大鼠吸烟一周后即出现体质量下降。深度抽吸及国标抽吸11mg焦油含量的卷烟均能显著诱导大鼠肺部巨噬细胞、淋巴细胞和中性粒细胞浸润，IL—1β和TNF-α分泌增加，以及MPO活性提高（均P〈0．05）；反映肺组织氧化应激水平的GSH含量和SOD活性均显著下降（均P〈0．05），活性氧和丙二醛含量则显著上升（均P〈0.05）。深度抽吸5mg焦油含量的卷烟能显著诱导淋巴细胞和中性粒细胞浸润、IL-1β和TNF-α分泌以及肺组织MPO活性上升，同时能显著促使肺组织中GSH含量及SOD活性下降以及活性氧和丙二醛含量增加（均P〈0．05）；但深度抽吸1mg焦油含量的卷烟无明显诱导炎症细胞浸润等作用。结论：口鼻式吸烟方式可以成功诱导大鼠肺损伤模型，大鼠肺部炎症细胞浸润程度、炎症因子分泌及氧化应激水平与主流烟气中有害物质含量成正比。

Objective： To investigate the effects of cigarette smoking in different manners on acute lung injury in rats. Methods： The commercially available cigarettes with tar of 1,5, 11 mg were smoked in Canada depth smoking （health canada method, HCM） manner, and those with tar of 11 mg were also smoked in international standard （ISO） smoking manner. Rats were fixed and exposed to mainstream in a manner of nose-mouth exposure. After 28 days, the bronchoalveolar lavage fluids from left lung were collected for counting and classification of inflammatory ceils and determination of proinflammatory cytokines IL-1β and TNF-α. The right lungs were subjected to histological examination and determination of myeloperoxidase （MPO） and superoxide dismutase （SOD） activities and glutathione, reactive oxygen species （ROS） and malondialdehyde （MDA） levels. Results： In both HCM and ISO manners, the degree of lung injury was closely related to the tar content of cigarettes, and significant decrease in the body weight of rats was observed after smoking for one week. In a HCM manner, smoking with cigarette of 11 mg tar resulted in robust infiltration of macrophages, lymphocytes and neutrophils into lungs, significant increase in IL-1β and TNF-α levels and MPO activities, and significant decrease in GSH levels and SOD activities and increase in ROS and MDA levels （ all P 〈 0.05 ）. Smoking with cigarette of 5 mg tar led to moderate increase in IL-1β and TNF-α levels, and MPO activities （ all P 〈 0.05 ）, and moderate decrease in GSH levels and SOD activities and increase of ROS and MDA levels （ all P 〈 0.05）. However, smoking with cigarette of 1 mg tar affected neither inflammatory cell infiltration nor IL-1β and TNF-α levels. Conclusion： Cigarette smoking in nose-mouth exposure manner can induce acute lung injury in rats; and the degree of lung injury is closely related to the content of tar and other hazards in cigarettes.