气管滴注大气可吸入颗粒物对大鼠的系统性氧化应激作用

Systemic oxidative stress induced by intratracheal instilling with PM_(10) in rats

目的:探讨大气可吸入颗粒物对大鼠的氧化应激作用。方法:将24只体重为320～360 g的雄性Wistar大鼠随机分为4组,即生理盐水对照组和颗粒物低、中、高剂量组(3.75、7.5、15 mg/kg)。染毒采用一次性气管滴注颗粒物,24 h后处死动物,测定血液中的超氧化物歧化酶(superoxide dismutase,SOD)活性和丙二醛(malondialde-hyde,MDA)含量,以及心肺组织中SOD活性、MDA和蛋白羰基(protein carbonyl)的含量。结果:与对照组相比,各染毒组大鼠血液中SOD活性降低,中、高剂量组的差异有统计学意义(P<0.05);血液中MDA含量升高,高剂量组的差异有统计学意义(P<0.05);各染毒组大鼠心肺组织高剂量组的SOD活性降低,且差异有统计学意义(P<0.05);肺脏MDA水平升高,中、高剂量组的差异有统计学意义(P<0.05);心脏MDA水平升高,高剂量组的差异有统计学意义(P<0.05);肺脏蛋白羰基含量升高,高剂量组的差异有统计学意义(P<0.05),心脏蛋白羰基含量无明显改变。结论:大气可吸入颗粒物能引起大鼠体内氧化和抗氧化系统的失衡,产生氧化应激效应,膜脂质较蛋白质更易受到氧化应激的作用。

Objective：To observe the oxidative stress of serum,lung and heart tissues in rats caused by PM10.Methods：In the study,24 male Wistar rats weighed 320-360 g were randomly divided into four groups,including one saline control group and three PM10 exposed groups.PM10 was administered to the exposed groups by intratracheal instillation at the doses of 3.75,7.5,15 mg/kg,respectively.The rats were sacrificed 24 hours after exposure.The levels of MDA and activities of SOD in the serum,lung and heart tissues were measured.In addition,the contents of protein carbonyl in lung and heart tissues were determined.Results：The activities of SOD in the serum,lung and heart tissues decreased markedly in the 7.5 and 15 mg/kg groups.The levels of MDA in the lung tissues significantly increased in the 7.5 and 15 mg/kg groups,while those in the serum and heart tissues significantly increased only in the 15 mg/kg group.The contents of protein carbonyl in the lung tissues markedly increased in the 15 mg/kg group,but no significant change was found in the heart tissues.Conclusion：The study showed that PM10 can cause oxidative stress effects in rats.The lipids of cell membrane are more susceptible to oxidative stress than the proteins.