典型滤光剂纳米二氧化钛与2-羟基-4-甲氧基二苯甲酮联合染毒及其在鲫鱼体内蓄积和对肝抗氧化酶活力的影响

Joint effects of n TiO_2 and BP3 on crucian carp:body accumulation and antagonism to the activities of antioxidant enzyme in liver

目的探讨典型滤光剂纳米二氧化钛与2-羟基-4-甲氧基二苯甲酮(BP3)联合染毒条件下,两者在鲫鱼不同组织的蓄积及对鲫鱼肝抗氧化酶活力的影响。方法将210尾健康12月龄雌性鲫鱼随机分成7组,分别为空白对照(曝气自来水)组、溶剂对照(0.01%甲醇)组和4、20μg/L BP3染毒组及100μg/L纳米二氧化钛染毒组以及4μg/L BP3+100μg/L纳米二氧化钛染毒组、20μg/L BP3+100μg/L纳米二氧化钛染毒组,每组30尾。采用半静态方式进行染毒,每天更换50%染毒溶液。分别在染毒7、14 d时,测定鲫鱼脑、肝脏、鳃、胆汁、肠、肌肉组织中纳米二氧化钛和BP3的含量及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GPx)的活力。结果空白对照组、溶剂对照组和纳米二氧化钛单独染毒组鲫鱼体内均未检出BP3。BP3单独染毒组中,BP3在鲫鱼肝和肠中的含量最高,分别为49.5~758.81 ng/g和40.12~890.32 ng/g;肌肉和胆汁的BP3含量最低,为4.38~24.72 ng/g。与相同浓度BP3单独染毒组比较,各浓度BP3+纳米二氧化钛联合染毒第7、14天时鲫鱼各组织中BP3的含量均较高,除肌肉和胆汁外,差异均有统计学意义(P<0.05);且随着BP3和纳米二氧化钛染毒浓度的升高及染毒时间的延长,鲫鱼各组织中BP3的含量均呈上升趋势。空白对照组、溶剂对照组和BP3单独染毒组鲫鱼体内均未检出纳米二氧化钛。与溶剂对照组比较,第7、14天时20μg/L BP3染毒组和20μg/L BP3+100μg/L纳米二氧化钛染毒组鲫鱼肝脏SOD、CAT和GPx活力升高,差异均有统计学意义(P<0.05);而空白对照组、4μg/L BP3染毒组、100μg/L纳米二氧化钛染毒组、4μg/L BP3+100μg/L纳米二氧化钛染毒组鲫鱼肝脏SOD、CAT和GPx活力均无明显变化。与相同浓度BP3单独染毒组比较,各浓度BP3+纳米二氧化钛染毒组鲫鱼肝脏SOD、CAT和GPx的活力升高,差异均有统计学意义(P<0.05)。结论纳米二氧化钛的存在促进了BP3在鱼体鳃、肝、肠和脑中的蓄积,20μg/L的BP3会提高鲫鱼肝抗氧化酶活力,且共存的纳米二氧化钛促进鱼体肝脏抗氧化酶活力的升高。

Objective To understand the combined toxic effects of nano-titanium dioxide（nTiO_2） and 2-hydroxy-4-methoxybenzophenone（BP3） on crucian carp,including the body accumulation of target compounds and the activities of antioxidant enzyme in the liver. Methods A total of 210 female fish aged one year were randomly divided into seven groups,blank control group（tap water after aeration）,solvent control group（0.01% methanol）,groups with different concentration of BP3 at 4 and 20 μg/L,nTiO_2 at 100 μg/L and the mixture of both,thirty fish in each group. The treatments were conducted with the half static way,half of the treatment solution were replaced every day,for fourteen consecutive days. The content of target compounds in fish brain,liver,gills,bile,digestive glands and muscle and the activities of catalase（CAT）,superoxide dismutase（SOD） and glutathione peroxidase（GPx） in fish liver were detected in the seventh and fourteenth days. Results BP3 was not detected in blank control group,solvent control group and 100 μg/L nTiO_2 exposure groups,BP3 mainly accumulated in the liver and digestive glands,in the range of 49.5-758.81 ng/g and 40.12-890.32 ng/g respectively,while the minimum content of BP3 occurred in the muscle and bile between 4.38 ng/g and 24.72 ng/g. A significant increase in BP3 accumulation in gills,liver,digestive glands and brain was further observed in the presence of nTiO_2 in the seventh and fourteenth days,the difference was statistically significant（P〈0.05）. The content of BP3 increased in fish with the increasing exposure time and concentration of BP3 and nTiO_2. Compared with solvent control group,the activities of the antioxidant enzyme CAT,SOD and GPx were significantly higher in 20 μg/L BP3 and 20 μg/L BP3＋100 μg/L nTiO_2groups（P〈0.05）. However the activities of the CAT,SOD and GPx were not significantly changed in blank control group,4 μg/L BP3,100 μg/L nTiO_2 and 4 μg/L BP3＋100μg/L nTiO_2 groups. All antioxidant enzyme activities were higher in joint-exposure of BP3＋nTiO_2 groups compared with those only exposed to BP3 with the same dose,the difference was statistically significant（P〈0.05）. Conclusion nTiO_2 may enhance BP3 accumulation in gills,liver,digestive glands and brain and BP3 exposure at 20 μg/L may induce all antioxidant enzyme activities in most cases,which maybe subsequently enhanced by co-exposed nTiO_2.