长期吸烟对大鼠肺E-选择素和IL-8表达影响

Effects of long-term smoking on expression of IL-8 and E-selectin in rat lungs

目的探讨长期吸烟对大鼠的肺损伤及相关炎性因子表达的影响。方法 56只雄性SD大鼠,随机分为对照组和低、中、高3个剂量吸烟组,采用自主开发的吸烟机给烟12周;放免法检测支气管肺灌洗液(BALF)中白介素-8(IL-8)的含量,免疫组化法检测肺血管内皮细胞E-选择素的表达水平。结果高、中、低剂量吸烟组大鼠BALF中IL-8的含量分别为(0.77±0.010)、(0.71±0.171)、(0.62±0.088)ng/mL,高于对照组(0.28±0.133))ng/mL,差异有统计学意义(P<0.01);高、中、低剂量吸烟组E-选择素的表达分别为(0.27±0.030)、(0.18±0.034)、(0.16±0.025),均高于对照组(0.07±0.023),差异有统计学意义(P<0.01);中剂量吸烟组肺血管内皮细胞E-选择素与BALF中IL-8的含量呈明显正相关(r=0.716,P<0.01)。结论长期吸烟导致气道炎症介质IL-8和E-选择素的表达升高,促进气道内炎症反应,对支气管肺组织造成严重损害。

Objective To investigate the influence of long-term smoking on the expression of inflammatory factors in rat lung tissue.Methods Fifty-six male SD rats were randomly divided into four groups：control,low-,moderate-,and high-dose group.The rats in each group were exposed to cigarette smoke at different dose for 12 weeks.The level of interleukin-8（IL-8） in bronchoalveolar lavage fluid（BALF） was measured with radioimmunoassay.Immunohistochemistry assay was carried out to examine the expression of E-selectin in lung tissue.Results The levels of IL-8 in BALF increased significantly in high-,moderate-,and low-dose group（0.77±0.010,0.71±0.171,and 0.62±0.088,respectively） compared to that of the control group（0.28±0.133,P0.01）.The expression of E-selectin in pulmonary vascular increased significantly in high-,moderate-,and low-dose group（0.27±0.030,0.18±0.034,and 0.16±0.025,respectively） compared to that of the control group（0.07±0.023,P0.01）.The level of IL-8 in BALF was positively correlated with the expression of E-selectin in moderate-dose group（r=0.716,P0.01）.Conclusion Long-term smoking can result in high expressions of IL-8 and E-selectin in airway and induce airway inflammation and cause serious damage in bronchial lung tissue in rats.