交通污染相关PM_(2.5)亚急性染毒对大鼠免疫功能的影响

Effects of subacute exposure to traffic pollution related PM_(2.5) on immune function in rats

目的建立交通污染相关PM_(2.5)大鼠亚急性染毒模型,研究其对大鼠肺泡巨噬细胞吞噬功能、体液免疫和细胞免疫功能的影响。方法将24只雄性SD大鼠随机分为4组,即对照组(生理盐水组)及低、中、高剂量PM_(2.5)染毒组(剂量分别为1.5、6、24 mg/kg)。采用气管内滴注PM_(2.5)混悬液的方式对大鼠进行染毒,隔天染毒1次,共染毒6次。采用中性红比色法测定肺泡巨噬细胞吞噬功能,MTT法检测T淋巴细胞增殖功能,ELISA法测定血清中IgG、IgM、IgA水平。结果大鼠肺泡巨噬细胞的吞噬功能随着染毒剂量的增加而下降,24 mg/kg PM_(2.5)染毒组大鼠的肺泡巨噬细胞吸光度(OD值)低于1.5 mg/kg PM_(2.5)组,差异有统计学意义(P<0.05)。大鼠脾脏T淋巴细胞增殖功能随着染毒剂量的增加而下降,各剂量PM_(2.5)染毒组大鼠刺激指数(SI)均低于对照组,差异有统计学意义(P<0.05)。大鼠血清IgG、IgM、IgA水平随着染毒剂量的增加而降低,6、24 mg/ml PM_(2.5)染毒组大鼠血清IgG水平低于对照组,1.5、6、24 mg/ml PM_(2.5)染毒组血清IgM、IgA水平低于对照组,差异均有统计学意义(P<0.05)。结论交通污染相关PM_(2.5)可能抑制大鼠的肺泡巨噬细胞吞噬功能、细胞免疫功能和体液免疫功能。

Objective To understand the effects of subacute exposure to traffic pollution related PM2.5on immune function of rats study. Methods A total of 24 male SD rats were randomly divided into four groups, normal saline control group, PM2.5low dose group, PM2.5moderate dose group and PM2.5high dose group（1.5, 6, and 24 mg/kg）. The exposure was conducted through tracheal instillation of PM2.5suspension, every the other day for six times. Alveolar lavage fluid was collected, neutral red colorimetric method was used to determine the function of the alveolar macrophage phagocytosis; The spleen cell suspension was prepared to determined T lymphocyte proliferation function by MTT method; The serum IgG, IgM and IgA levels were detected by ELISA method. Results Alveolar macrophage phagocytosis of rats decreased with the increase of PM2.5dose, there was significant difference between the high PM2.5dose group and low PM2.5dose group（P 〈0.05）; Spleen T lymphocyte proliferation functions of rats was inhibited with the increase of PM2.5dose, comparing with normal saline group, spleen T lymphocyte proliferation functions in each PM2.5group decreased significantly（P 〈0.05）; Except for the low dose group, the serum IgG levels in the other two PM2.5groups significantly reduced compared with normal saline group（P〈0.05）; The serum IgM and IgA levels in all PM2.5groups significantly decreased compared with the saline group（P〈0.05）. Conclusion Traffic pollution related PM2.5can inhibit alveolar macrophage phagocytosis, cellular immune function and humoral immune function in rats.