三氯异氰尿酸对斑马鱼胚胎及幼鱼的发育毒性

Developmental toxicity of trichloroisocyanuric acid on zebrafish embryos and larvae

目的探讨新型消毒剂三氯异氰尿酸(TCCA)对斑马鱼胚胎及幼鱼的发育毒性。方法选择受精后2 h的斑马鱼胚胎进行染毒:①将胚胎置于含有TCCA 50,100,150,200,250和300 mg·L^(-1)的培养液中暴露48 h,检测半数致死浓度(LC_(50))。②将胚胎置于含有TCCA 0,10.4,20.8和41.7 mg·L^(-1)的培养液中暴露96 h,分别于暴露后48,72和96 h检测胚胎死亡率、畸形率和心率,采用羟胺法于暴露后2,4和6 h检测胚胎组织超氧化物歧化酶(SOD)的活性,HE染色观察暴露后7 d幼鱼头部组织病理结构。结果 TCCA暴露48 h,斑马鱼胚胎LC_(50)为166.9 mg·L^(-1)。与正常对照组相比,暴露后96 h,TCCA 41.7 mg·L^(-1)组斑马鱼胚胎死亡率和畸形率显著升高(P<0.05),TCCA各剂量组心率显著下降(P<0.05);暴露后72h,TCCA41.7mg·L^(-1)组死亡率显著升高(P<0.05),20.8和41.7mg·L^(-1)组畸形率显著升高(P<0.05),心率显著下降(P<0.05);暴露后48 h,TCCA 41.7 mg·L^(-1)组畸形率显著升高(P<0.05)、心率显著下降(P<0.05)。TCCA暴露4和6 h,20.8和41.7 mg·L^(-1)组SOD活性较正常对照组显著下降(P<0.05)。TCCA暴露7 d后,与正常对照组相比,各浓度组斑马鱼幼鱼均出现脑和眼部间隙变大及眼部视网膜分层不明显的病理改变。结论 TCCA对斑马鱼胚胎发育有毒性作用,能引起胚胎发育早期SOD活性下降,造成幼鱼视网膜组织结构损伤。

OBJECTIVE To investigate the developmental toxicity of a new disinfectant trichloroisocyanuric acid（TCCA） on zebrafish embryos and larvae. METHODS Zebrafish embryos of 2 h post fertilization（hpf） were exposed to TCCA： ① The embryos were exposed to a culture medium containing TCCA 0, 50, 100, 150, 200, 250 and 300 mg·L^-1 for 48 h before 50% lethal concentration（LC（50）） was calculated. ② The embryos were exposed to a culture medium containing TCCA 0, 10.4, 20.8 and41.7 mg · L^（-1） for 96 h. The mortality, malformation rate and heart rate of embryos and larvae were measured at 48, 72 and 96 h after TCCA exposure. The expression of superoxide dismutase（SOD）was detected at 2, 4 and 6 h after TCCA exposure. The pathological changes in the head of zebrafish larvae were observed 7 d after exposure by HE staining. RESULTS LC（50）of 48 h after TCCA exposure was 166.9 mg·L^-1. Compared with normal control group, the mortality and malformation rate of zebrafish embryos were significantly increased（P0.05） in TCCA 41.7 mg · L^（-1） group, but the heart rate was decreased significantly（P0.05） in each dose of TCCA group at 96 h after TCCA exposure. At 72 h after TCCA exposure, the mortality rate of zebrafish embryos was significantly increased（P0.05） in TCCA41.7 mg·L^-1 group, the malformation rate of zebrafish embryos was increased（P0.05） and the heart rate of zebrafish embryos was decreased（P0.05） in 20.8 and 41.7 mg · L^（-1） groups. At 48 h after TCCA exposure, the heart rate of zebrafish embryos was decreased significantly（P0.05） in 41.7 mg · L^（-1）group. The SOD activity of zebrafish embryos in 20.8 and 41.7 mg·L^-1 groups was significantly lower than that of control group（P0.05）. At 7 d after exposure, the brain and ocular space of larvae were enlarged and the ocular retina layers were not obvious in any dose of TCCA groups. CONCLUSION TCCA has toxic effect on zebrafish embryonic development, which can down-regulate SOD activity in the early developmental stage of embryos and damage the retina tissue of larvae.