高温及低温时大气PM_(2.5)对大鼠肺泡巨噬细胞的毒性作用

目的探讨高低温下大气PM_(2.5)对肺泡巨噬细胞(alveolar macrophages,AMs)的毒性作用及机制。方法取大鼠AMs进行原代培养,并在高温(43℃)、低温(31℃)及正常温度(37℃)下分别给予0、25、50、100μg/ml PM_(2.5)染毒,倒置显微镜下观察AMs的形态和数量变化,测定AMs的相对细胞存活率、吞噬功能及培养液中炎症因子等指标。结果低温、常温和高温时PM_(2.5)高剂量组的大鼠AMs细胞存活率分别为47.9%,62.2%和32.3%,AMs的细胞活性和吞噬功能均随着PM_(2.5)剂量的升高而降低,且在低温或高温时明显低于正常温度组,差异有统计学意义(P0.05)。低温或高温与PM_(2.5)对AMs炎症因子生成的影响无交互作用,但均可增加PM_(2.5)对AMs中SOD活力的抑制作用,差异有统计学意义(P0.05),且高温的抑制作用更强,高、低温时高剂量组大鼠的细胞SOD活力分别为44.54、51.31 U/ml。结论高低温下,大气PM_(2.5)对AMs的毒性作用增强,可能通过降低SOD活力而降低其细胞活性和吞噬功能,且高温的影响强于低温。

Toxic effects of ambient PM2.5 exposure on rat alveolar macrophage under high and low temperature

Objective To explore the toxic effects of ambient PM2.5 (fine particulate matter) on AMs (alveolar macrophages) under high and low temperature and the related mechanism.Methods AMs,harvested from male rats,were primarily cultured and exposed to different doses of PM2.5 (0,25,50 and 100 μg/ml) under different temperature (31,37 and 43 ℃),respectively,then the morphological and quantity changes were observed with inverted microscope,the viability and phagocytic activity of AMs along with the level of inflammatory cytokines and oxidative damage factor in culture medium were detected.Results In all temperature groups,the viability of high dosage was respectively 47.9％,62.2％ and 32.3％,and the viability and phagocytosis activity of AMs declined significantly as the dosage of PM2.5 increased,which in high or low temperature group was significantly lower than normal temperature group.High and low temperature had no obvious effects on the secretion of inflammatory factors when AMs were exposed to ambient PM2.5,but inhibited the activity of SOD,the activity of SOD declined to 44.54 U/ml and 51.31 U/ml respectively.Conclusion The toxic effects of ambient PM2.5 on AMs may be enhanced by high and low temperature,perhaps by the way of inhibiting the activity of SOD to suppress the viability and phagocytic activity of AMs,and the effects of high temperature are stronger compared with low temperature.