硝酸铊对斑马鱼胚胎的发育毒性

Developmental Toxicity of Thallium Nitrate to Zebrafish Embryos

以斑马鱼(Danio rerio)为研究对象,将受精后1 h内的斑马鱼胚胎持续暴露于0~1 000 μg/L的TlNO3溶液中168 h,研究TlNO3处理对斑马鱼形态发育、心率、SOD酶、CAT酶及幼鱼行为的影响。结果表明:不同浓度TlNO3处理168 h后,斑马鱼幼鱼出现鱼鳔发育受阻、心囊水肿、脊柱弯曲、血液循环减弱、心率减缓和胚胎发育阻滞等现象;暴露24 h后50~1 000 μg/L TlNO3处理组斑马鱼的SOD与CAT酶活性即显著低于对照,随着处理时间的延长,TlNO3对斑马鱼氧化应激相关酶的高毒性表现出剂量-效应关系,即硝酸铊浓度越高,SOD及CAT酶活性降低程度越大;与对照组幼鱼行为相比,5 μg/L硝酸铊处理组斑马鱼幼鱼活动增多、紊乱,行为强度大;50 μg/L硝酸铊处理组斑马鱼幼鱼出现行为迟缓、呆滞及活动减少等现象。综上所述,TlNO3胁迫可使斑马鱼胚胎发育阻滞、组织器官功能被破坏、抗氧化防御系统严重失衡,自发性活动行为受到影响。

Zebrafish (Danio rerio) embryos within 1 h post-fertilization were continuously exposed to 0-1 000 μg/L of thallium nitrate solution (TlNO3) for 168 h to study the effects of TlNO3 treatments on morphological development,heart rate,SOD (superoxide dismutase) and CAT (catalase) activities and behavior of juvenile zebrafish.The results showed various concentrations of TlNO3 treatments caused impaired swim bladder development,pericardial edema,reduced blood circulation,spinal curvature,slowed heart rate and retardant embryonic development in juvenile zebrafish over the 168 h period.After 24 h of exposure,the SOD and CAT activities in 50-1000 μg/LTlNO3 treatment groups decreased significantly compared with the control group.The high toxicity of TlNO3 on zebrafish oxidative stress-related enzymes was shown by the fact that the higher the concentration of TlNO3,the greater the reduction in oxidative stress enzyme activity,showing a dose-effect relationship.Compared with the control group,the behavior of juvenile zebrafish in the 5 μg/L treatment group showed increased activity,disorder and high behavioral intensity,while in the 50 μg/L treatment group showed retardation,sluggishness and reduced activity.These results suggest that TlNO3 can block the development of zebrafish embryos,damage the functions of tissues and organs,cause serious unbalance of the antioxidant defense system,and influence the spontaneous activity behavior.