【摘要】 目的利用动物实验比较不同地区大气PM2.5对呼吸系统的毒性作用。方法采集广州、东莞、深圳和肇庆4个城市的大气PM2.5。将雄性SD大鼠分为3个染毒组(10、3和1 mg/kg)和1个对照组,每组7只。4个城市的PM2.5均按此分组并染毒。气管滴注PM2.5,对照组滴注等量生理盐水。分别于48 h和28 d后处死动物,收集左侧肺和一定量的肺泡灌洗液(BALF),观察肺部病理变化和测定灌洗液中总蛋白(TP)、超氧化物歧化酶(SOD)、乳酸脱氢酶(LDH)、白介素-6(IL-6)和肿瘤坏死因子(TNF-α)的变化。结果肇庆地区大鼠体重增长率较高,东莞地区最低。PM2.5主要导致间质炎性细胞浸润、支气管炎症等。与对照组比较,PM2.5导致肺泡灌洗液中TP、LDH、IL-6和TNF-α水平增高,SOD活力降低,差异有统计学意义(P<0.05)。广州PM2.5组LDH的漏出量最高,深圳PM2.5组肺泡灌洗液中SOD活力最低,东莞PM2.5组肺泡灌洗液中IL-6释放量最高,肇庆PM2.5染毒48 h组SOD活力均高,LDH、TNF-α、IL-6均较低。结论本次采集的四城市大气PM2.5可致大鼠肺组织发生氧化应激损伤和炎性反应。广州、东莞、深圳PM2.5对上述效应指标的影响强于肇庆。更多还原

【Abstract】 Objective To compare the toxicity of PM2.5 collected from different cities of China through an animal experiment.Methods Airborne particulate matter PM2.5 was collected in four cities of south China,Guangzhou,Shenzhen,Dongguan and Zhaoqing at the same time period.Experimental animals were SD rats,which were divided into three dosage groups and one control group,seven in each.Particulate matters were administered to rats for one time by intratracheal instillation at the dose of 10 mg/kg,3 mg/kg,and 1mg/kg respectively,and with the same volume of saline for control group.The rats were sacrificed 48 hours or 28 days after the treatment,and then left lung and bronchoalveolar lavage fluid(BALF) was collected.These biological samples were used to observe the change of lung pathology and measure the levels of TP,LDH,SOD,IL-6 and TNF-α in BALF.Results The rate of animal body weight increase in Zhaoqing and control group was the highest,the lowest one was found in Dongguan group,moderate level was found in Shenzhen and Guangzhou group.Pathological changes were observed in all particulate groups,with inflamation signs of pulmonary interstitial and bronchus.The level of TP,LDH,IL-6,and TNF-α increased significantly while SOD decreased significantly in BALF with the increase in particulate dose compared with the control group(P<0.05).If comparing the two experiments of different times,the parameters observed after particle exposure for 48 hours changed more significantly than that of exposure for 28 days(P<0.05).When comparing between regions,the Guangzhou PM had the strongest toxicity in leakage of LDH.Shenzhen PM had the highest toxicity in reduction of SOD activity.The Dongguan PM had the strongest toxic effects in producing IL-6.In contrast,the toxicity of Zhaoqing PM was at the lowest level in all aspects.Conclusion The particle matters from the cities of Guangzhou,Dongguan and Shenzhen showes the stronger toxicity than the reference group of Zhaoqing,which seems to be related to the haze whether and thereby the component of particulate matters.All the parameters changed significantly in the time period of 48 h after exposure than that of the 28 d group.Oxidative stress and inflammation may play an important role in the mechanism.更多还原