百草枯对斑马鱼的生理指标和胚胎发育影响
Effects of Paraquat on Physiological Indicators and Embryos Development of Zebrafish
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摘要:
目的 探讨百草枯(paraquat,PQ)对斑马鱼(zebrafish,Danio rerio)的生理指标和胚胎发育影响,并确定其最大未观察到有害作用浓度(NOAEC)。 方法 参照经济合作与发展组织(OECD)推荐的方法,采用百草枯急性暴露试验、亚急性暴露试验及胚胎发育毒性试验进行研究。斑马鱼及其胚胎通过水环境暴露接触百草枯后,分别测定半数致死浓度(LC50)、乙酰胆碱酯酶(AChE)、超氧化物歧化酶(SOD)、腺苷三磷酸酶(ATPase)活性、孵化率、死亡率、畸变率等指标。 结果 百草枯对斑马鱼的96 h LC50 为35.71 mg/L(95%可信区间:26.41~51.30 mg/L),属中等毒性类除草剂。0.9 mg/L 浓度的百草枯对SOD活性有诱导增强作用;3.6~7.2 mg/L 浓度的百草枯对SOD、ATPase、AChE活性有抑制作用,对肝、肾有病理性损伤作用。百草枯对斑马鱼胚胎的发育也有明显影响,对照组与百草枯各暴露组的120 hpf(受精后120 h,120 hours post fertilization)孵化率分别为96%、90%、78%和44%,120 hpf 死亡率分别为2%、4%、12%和28%,120 hpf 畸变率分别为2%、2%、6%和18%。与对照组相比,0.10 mg/L 和0.50 mg/L 百草枯处理组的胚胎发育迟缓,仔鱼体长、体宽缩短,差异有统计学意义;而0.02 mg/L 浓度组的斑马鱼胚胎发育未见明显异常。 结论 百草枯能引起斑马鱼病理、生理指标的改变,可延缓斑马鱼胚胎发育,具有胚胎致死和胚胎致畸毒性。百草枯的NOAEC为0.02 mg/L。 Abstract:Objective To study the effect of paraquat(PQ)on zebrafish(Danio rerio)physiological indicators and its embryonic development with its no-observed-adverse-effect-concentration(NOAEC)were determined. Methods According to the method recommended by Organization for Economic Co-operation and Development(OECD), the impact of PQ in zebrafish was evaluated with acute exposure test, subacute exposure test and zebrafish embryos developmental toxicity test. Results Based on the results of probability unit-graphic calculation, 50% lethal concentration(LC50)(96 h)in zebrafish of PQ was 35.71 mg/L(95% confidence interval:26.41-51.30 mg/L). It was suggested that the test substance was a moderately toxic phytocide after an acute exposure. After being exposed to sub-lethal concentrations of PQ for 96 h, significant effects of PQ on SOD, AChE and ATPase activity of zebrafish were detected, the pathologic damage of PQ on liver, kidney were observed. Comparing with the control group, the activity of SOD in livers for experimental groups was significantly induced and enhanced in concentration of 0.9 mg/L; the activity of SOD, ATPase and AChE in livers was decreased in concentration of 3.6-7.2 mg/L. The impact of PQ to zebrafish embryos development was also observed. The 120 hpf hatching ratios of control groups and various concentration groups were 96%, 90%, 78%, and 44% respectively. The 120 hpf death rates were 2%, 4%, 12%, and 28%; and the 120 hpf teratogenicity rates were 2%, 2%, 6%, and 18% respectively. Compared with the control group, retardation of embryo development in 0.10 mg/L and 0.50 mg/L PQ-treated groups were observed obviously. Although no significant differences were detected on body weight, the body length and body width were significantly shrinked in 0.1 mg/L and 0.5 mg/L PQ-treated groups, while comparing with control group. No obvious embryos development abnormalities were observed in 0.02 mg/L PQ-treated groups. Conclusion PQ exposure caused physiological and pathological changes in zebrafish. PQ delayed embryonic development and even resulted in embryonic lethality and induced the malformation in zebrafish. Under the experimental conditions, the NOAEC of PQ to zebrafish was 0.02 mg/L.
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