载带苯并[a]芘的纳米碳／二氧化硅颗粒引起大鼠氧化应激作用的研究

通过人工制备载带Ba]P的纳米碳(C)和纳米二氧化硅(SiO2)颗粒,采用气管滴注染毒方式,以7.5mg·kg-1(以体重计)的染毒剂量急性染毒大鼠,观察染毒24小时后载带Ba]P的纳米C/SiO2颗粒对机体产生氧化应激损伤的联合毒性效应.结果表明,在急性染毒后大鼠外周血中反映机体脂质过氧化损伤程度指标的丙二醛(MDA)含量表现为染毒组较对照组显著增加(p<0.05),表明纳米颗粒诱发机体发生了氧化应激反应.在急性染毒后各组大鼠肺泡灌洗液中谷胱苷肽过氧化物酶(GSH-PX)和超氧化物岐化酶(T-SOD)活力与对照组相比显著增加(p<0.05)(载带Ba]P的纳米SiO2组除外);载带Ba]P的纳米SiO2组肺泡灌洗液中GSH-PX活力与对照组相比无显著差异,而与单纯纳米SiO2组和Ba]P组比较显著降低,推测与抗氧化酶的一过性增高有关;载带Ba]P的纳米C组肺泡灌洗液T-SOD活力与其单纯纳米C组和单纯Ba]P组比较显著增加(p<0.05),由此表明载带Ba]P的复合纳米C/SiO2颗粒在致机体氧化损伤效应方面二者存在一定的协同作用.

Study on the Oxidative Stress of Rats Induced by Benzo[a]pyrene Coated onto Nano Carbon / Silicon Dioxide Particles

The aim of this study was to evaluate the oxidative stress association toxicity in rats of intratracheally instilled nano carbon(C)/silicon dioxide(SiO2)coated onto benzoa]pyrene (Ba]P). Groups of rats were intratracheally instilled with doses of 7.5mg·kg-1 body of the following particle-types: 1) nano C particles; 2) nano SiO2 particles; 3) Ba]P; 4) the prepared nano C coated onto Ba]P particles; 5) the prepared nano SiO2 coated onto Ba]P particles; 6) micro milk liquid(1.0% olive oil, 2.0% tween 80 in phosphate-buffered saline) instilled rats served as controls. Following exposures, the lungs of control and particle-exposed rats were evaluated for peripheral blood and bronchoalveolar lavage(BAL) fluid oxidative damage markers at post-instillation 24h. For the treatments the content of lipid peroxidation(malondialdehyde, MDA) in peripheral blood of rats was significantly higher than that of control groups(p<0.05), which indicated nanparticles induced oxidative stress. The BAL demonstrated that lung exposures to nano particles produced significant increases vs. controls in the enzyme activity of GSH-PX and T-SOD(except nano SiO2 coated onto Ba]P; Exposures to nano SiO2 coated onto Ba]P particles produced no significant difference vs. controls, but decreased significantly vs. nano SiO2 and Ba]P lonely in GSH-PX, likely related to the effects of the transient increase in anti-oxidative enzyme. Exposures to nano C coated onto Ba]P particles produced significant increases vs. both single nano C and Ba]P in T-SOD(p<0.05). The results indicate that exposure to Ba]P-coated onto nano C/SiO2 particles is likely more deleterious by virtue of their combinations being able to cause association oxidative stress than either chemical alone.