沙尘暴源区土壤盐碱扬尘对大鼠呼吸系统的免疫损伤

为研究沙尘暴源区土壤盐碱扬尘对大鼠呼吸系统的免疫损伤,采集距北京200多公里的张家口张北地区的安固里诺尔干盐湖(N41.316°,E114.350°)0~5 cm的盐碱表土,过200目(75μm)筛,测试土壤盐碱扬尘中水溶性离子。将32只雄性7周龄Wistar大鼠随机分为4组,即生理盐水对照组、低浓度组(1.5 mg·kg~(-1))、中浓度组(7.5 mg·kg~(-1))、高浓度组(37.5 mg·kg~(-1)),配制颗粒物悬液,采用气管滴注急性染毒方式,24 h后处死动物,检测血常规及血浆和肺泡灌洗液(BALF)的总抗氧化能力(T-AOC)、白介素-6(IL-6)、肿瘤坏死因子(TNF-α)、乳酸脱氢酶(LDH)、转化生长因子(TGF-β1)等氧化炎症因子,并制作肺组织和气管病理切片。结果表明,沙尘暴源区土壤盐碱扬尘中含有大量的SO_4~(2-)、NO_3~-和NH_4~+等离子;土壤盐碱扬尘急性染毒会对大鼠气管和肺组织造成明显的炎症病变,并随着染毒试剂浓度的升高而加重;但对大鼠血常规的影响较小。中、高浓度染毒使血浆中T-AOC显著下降(P0.05);染毒促使血浆TGF-β1分泌显著增加(P0.05),但不存在剂量-效应关系,其他氧化炎症指标分泌无显著变化。中、高浓度组BALF的TGF-β1因子分泌量显著高于生理盐水对照组(P0.05),高浓度组BALF中IL-6含量显著低于生理盐水对照组(P0.05),其他氧化炎症指标分泌无显著变化。这些研究显示土壤盐碱扬尘粒径大小及化学成分可能是造成大鼠氧化炎症差异的原因。

Immunologic Injuries on Respiratory System of Rats Induced by Saline-alkali Soil Dust from Dust Storm Source Region

To study the immunologic injury on the respiratory system of rats induced by saline-alkali soil dust from the dust storm source region, saline-alkali soil samples were collected from Angulinuo Playa Lake (N41.316°, E114.350°) in Zhang Jiakou City, which is a dust storm source area and about more than 200 kilometers away from Beijing. Samples were shaken and sieved through a 200-mesh strainer (<75μm). Some samples were measured for water-soluble ions, and others were used to carry out acute intratracheal instillation exposure experiments on 32 eight-week-old rats, that were randomly divided into 4 exposure level groups including saline control group (SG), low-dose group (LG) with 1.5 mg·kg-1 dust, medium-dose group (MG) with 7.5 mg·kg-1 dust and high-dose group (HG) with 37.5 mg·kg-1 dust. 24 hours later all rats were killed by ether anesthesia, routine blood test and six in-flammatory indexes of blood plasma and bronchoalveolar lavage fluid (BALF) were tested. Results showed that the saline-alkali soil is rich in SO42-, NO3-and NH4+. Histopathological observation indicated that obvious inflammato-ry injuries of trachea and lung occurred in dust treated rat groups, showing increased damage with higher doses. In blood serum, T-AOC levels of MG and HG were significantly lower than that of SG (P<0.05), and TGF-β1 levels of all dose groups were significantly higher than that of SG (P<0.05). Similarly, TGF-β1 levels of MG and HG were significantly higher than that of SG (P<0.05) in BALF, whilst the IL-6 level of HG was significantly lower than that of SG (P<0.05). There were no statistical differences in TNF-α, LDH and the various index of the routine blood test. Soil dust size and chemical components may induce different immunologic injuries of the respiratory system and reaction of the oxidative inflammatory index in rats.