纳米材料对斑马鱼的氧化损伤及应激效应研究

Oxidative Stress Effects and Damage of Nanoscale TiO_2 and ZnO on Zebrafish

以斑马鱼(Daniorerio)为受试动物,研究了纳米及常规TiO2、ZnO悬浮液对其鳃、消化道及肝脏的氧化损伤及应激效应,同时对纳米及常规TiO2、ZnO悬浮液中的颗粒形貌特征及·OH生成量进行了测定.结果发现,虽然纳米TiO2、ZnO颗粒与其常规颗粒在溶液中的粒径分布接近,但50mg/L纳米TiO2、ZnO悬浮液中·OH产生量(96h光照下,分别为2.17mmol/L、0.72mmol/L)远远高于50mg/L常规颗粒(未检测到).50mg/L纳米TiO2处理下,斑马鱼肝脏中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、还原型谷胱甘肽(GSH)、蛋白质羰基含量分别为对照的70.2%、65.4%、53%、178.1%;消化道中SOD活性及GSH、丙二醛(MDA)含量分别为对照的149.6%、212.9%、217.2%;鳃中MDA含量为对照的160.9%.而50mg/L常规TiO2悬浮液对斑马鱼没有产生毒理效应.5mg/L纳米及常规ZnO对斑马鱼肝脏的氧化伤害最强,其中5mg/L纳米ZnO处理组中SOD、CAT活性及GSH、MDA含量分别为对照的62.9%、53.1%、45.2%、204.2%,5mg/L常规ZnO处理组中SOD、CAT活性及GSH、MDA含量分别为对照组48.3%、51.8%、34.6%、289.6%;虽然斑马鱼鳃及消化道也受到明显氧化应激效应(p<0.05),但并没有受到氧化损伤.研究表明,团聚作用对不同化学组成纳米颗粒的毒性影响程度不同;且不同化学组成纳米颗粒在生物体内可能通过不同机制产生了不同种类的ROS,从而对不同细胞组分产生的氧化损伤及应激效应是其重要的毒理机制.

The oxidative stress effects and damage of nanoscale zinc oxide （ nZnO）,titanium dioxide （ nTiO2 ） and their bulk counterparts （i. e. ,ZnO/bulk,TiO2 /bulk） suspension on gill,intestine and liver of zebrafish （Danio rerio） were studied,as well as the characterization of nZnO,nTiO2 ZnO/bulk and TiO2 /bulk and the amount of ·OH in suspension in the presence of light were studied. The results show that the size distribution of nanoparticle and bulky particle are similar in suspension,while the amount of ·OH in 50 mg/L nTiO2,nZnO suspension are2.17 mmol/L,0.72 mmol/L respectively in the presence of96 h illumination,which is much higher than that of 50 mg/L bulky particle suspension（not detected）. As exposed to 50 mg/L nTiO2 suspension,in contrast to control,the superoxide dismutase （SOD）,catalase（CAT） and reduced glutathione （GSH）,protein carbonyl content in liver tissue of zebrafish are 70. 2% ,65. 4% ,53% ,178. 1% respectively,and the SOD activity and GSH,malondialdehyde （ MDA） content in digestive tract are 149. 6% ,212. 9% and 217. 2% respectively. The MDA content in gill is 160. 9% than that of control as exposed to 50 mg/L nTiO2 suspension. However,there are no toxic effects on zebrafish after 96 h exposure to 50 mg/L TiO2 /bulk suspension. The strongest oxidative damage is found in liver tissue of zebrafish as exposed to 5 mg/L nZnO and ZnO/bulk suspension for 96 h. In contrast to control,the SOD,CAT activity and GSH,MDA content are 62. 9% ,53. 1% ,45. 2% and 204. 2% after 96 h exposure to 5 mg/L nZnO suspension,and 48. 3% ,51. 8% ,34. 6% ,289. 6% after 96 h exposure to 5 mg/L ZnO/bulk suspension. Significant oxidative stress is also found both in gill and intestine. However,there is no oxidative damage on gill and intestine. The experiment results indicated that the effects of agglomeration on nanoparticle of different chemical composition are various. The oxidative stress and damages induced by reactive oxygen species （ ROS） which generated through different way by nanoparticle of different chemical composition might play a role in the bio-toxicity of nanoparticle.