潍坊市城区大气PM_(2.5)致小鼠外周血淋巴细胞微核试验

Micronucleus test of PM_(2.5) in Weifang city to mice peripheral blood lymphocytes

目的了解潍坊市城区大气PM_(2.5)对小鼠外周血淋巴细胞的遗传毒性。方法收集2013年12月(采暖期)和2014年4月(非采暖期)潍坊市城区大气监测数据,包括SO_2、NO_2、PM_(10)、CO、O)3、PM_(2.5)和空气质量指数(AQI)。同时采集潍坊城区大气PM_(2.5)并制备成不同浓度的颗粒物悬液。将48只小鼠随机分为6组,每组8只,即阴性对照组(生理盐水)、阳性对照组(环磷酰胺)、采暖期高剂量组、采暖期低剂量组、非采暖期高剂量组、非采暖期低剂量组,采用气管滴注方式进行染毒,染毒容量为0.3 ml/kg(低剂量组:1.5 mg/kg;高剂量组:7.5 mg/kg),每日1次,连续染毒14 d。采用胞质分裂阻滞微核试验检测其细胞毒性及遗传损伤情况。结果采暖期大气SO)2、NO)2、CO、O)3、PM_(10)、PM_(2.5)和AQI的日平均值均高于非采暖期,差异均有统计学意义(P<0.05)。胞质分裂阻滞微核试验显示,对于相同采样期,采暖期高剂量组双核细胞率、核分裂指数低于低剂量组,坏死细胞率、微核率、核芽率高于低剂量组;非采暖期高剂量组坏死细胞率高于低剂量组,差异均有统计学意义(P<0.05)。对于相同剂量组,非采暖期低剂量组微核细胞率、核质桥率低于采暖期;非采暖期高剂量组双核细胞率、核分裂指数高于采暖期,坏死细胞率、微核细胞率、微核率、核质桥率、核芽率低于采暖期,差异均有统计学意义(P<0.05)。结论采暖期PM_(2.5)可使小鼠外周血淋巴细胞微核率增加,并有较强的细胞毒性。

Objective To study the genotoxicity of PM_(2.5) on the mouse lymphocytes.Methods The data of air monitoring in Weifang city in December 2013(heating period) and April 2014(non-heating period) were collected,including:SO_2,PM_(10),NO_2,CO,O_3,PM_(2.5)and air quality index(AQI).In December 2013(heating period) and April 2014(non-heating period) PM_(2.5)particles in the Weifang city were collected,and dissolved with normal saline into different concentrations of particulate matter suspension.A total of 48 mice were randomly divided into six groups,eight mice in each group,the negative control group(normal saline),high PM_(2.5)dose group in heating period,low PM_(2.5)dose group in heating period,high dose group in non-heating period,low dose group in non-heating period,positive control group(cyclophosphamide).The particulate matter suspension was injected into mice through the trachea with 0.3 ml/kg(1.5 mg/kg for low dose group,7.5 mg/kg for high dose group),once a day,14 days in a row.The cytokinesis block micronucleus test was carryed out to detect the cytotoxicity and genetic damage of mice induced by PM_(2.5).Results The daily average levels of SO_2、NO_2、CO、O_3、PM_(10)、PM_(2.5)and AQI in heating period were significantly higher compared with those in non-heating period(P<0.05).Cytokinesis block micronucleus test results showed that,in heating period,lower levels of dual core cell rate and the nuclear division index and higher levels of necrosis rate,micronucleus rate,and nuclear buds rate were observed in high dose group compared with those in low dose group(P<0.05);In non-heating period,higher necrosis rate was observed in high dose group compared with that in low dose group(P<0.05).In low dose group,lower levels of micronucleus cells rate and nucleoplasmic bridges rate were observed in non-heating period compared with those in heating period(P<0.05).In high dose group,higher levels of dual core cell rate and the nuclear division index,lower levels of necrosis rate,micronucleus cells rate,micronucleus rate,nucleoplasmic bridges rate,nuclear buds rate,were observed in non-heating period compared with those in heating period(P<0.05).Conclusion Fine particles in heating period would induce the micronucleus rate of peripheral blood lymphocytes and the cytotoxicity to mice.