Pulmonary effects of inhaled diesel particles in rats

The pulmonary response to inhalation exposure to diesel exhaust particles (DEP) was investigated in a rat model. Adult male Sprague-Dawley rats were exposed by whole-body inhalation to air or an aerosol containing DEP at concentrations of 200 or 1000 mg/m3, 6 hours/day for 4 days. The control and DEP-exposed rats were euthanized at post-exposure time intervals of 1, 7, or 27 days and pulmonary inflammatory, cytotoxic and oxidant responses were determined. Analysis of bronchoalveolar lavage parameters of toxicity such as lactate dehydrogenase activity, oxidant generation, and inflammation did not reveal any significant pulmonary toxicity in the DEP-exposed rats. The lung gene expression profiles did not change significantly in the DEP exposed rats compared with the controls. The data obtained from the present study demonstrated that DEP inhalation exposure under the conditions employed in the present study did not result in any significant lung toxicity in the rats.本研究采用大鼠模型，探究了吸入暴露于柴油排气颗粒物（diesel exhaust particles，DEP）后的肺部应答情况。将成年雄性斯普拉格-道利（Sprague-Dawley）大鼠通过全身吸入方式暴露于空气，或暴露于浓度为200 mg/m³、1000 mg/m³的含DEP气溶胶中，每日暴露6小时，连续暴露4天。分别于暴露后1、7、27天三个时间点对对照组及DEP暴露组大鼠实施安乐死，并检测其肺部炎症、细胞毒性及氧化应激应答水平。对支气管肺泡灌洗（bronchoalveolar lavage，BAL）的毒性相关参数（如乳酸脱氢酶（lactate dehydrogenase，LDH）活性、氧化产物生成量及炎症指标）进行分析后发现，DEP暴露组大鼠未出现显著肺部毒性反应。与对照组相比，DEP暴露组大鼠的肺部基因表达谱未发生显著变化。本研究获取的数据表明，在本研究采用的暴露条件下，吸入DEP不会使大鼠产生显著的肺部毒性反应。