Centre for Environmental Radioactivity (CERAD CoE), NMBU, 1433 Ås, Norway; Norwegian University of Life Sciences (NMBU), Faculty of Veterinary Medicine and Biosciences, P.O. Box 8146 Dep., 0033 Oslo, Norway.
Norwegian University of Life Sciences (NMBU), Faculty of Veterinary Medicine and Biosciences, P.O. Box 8146 Dep., 0033 Oslo, Norway.
Ecotoxicol Environ Saf. 2018 Dec 30;166:359-365. doi: 10.1016/j.ecoenv.2018.09.082. Epub 2018 Oct 1.
Environmental UV radiation in sufficient doses, as a possible consequence of climate change, is potent enough to affect living organisms with different outcomes, depending on the exposure life stage. The aim of this project was to evaluate the potentially toxic effects of exposure to sub-lethal and environmentally relevant doses of UVA (9.4, 18. 7, 37.7 J/cm) and UVB radiation (0.013, 0.025, 0.076 J/cm) on the development and behaviour in early life stages (4.5-5.5 h post fertilization, hpf) of the zebrafish (Danio rerio). The used doses were all below the median lethal dose (LD) and caused no significant difference in survival, deformities, or hatching between exposed and control groups. Compared to controls, there were transient UVA and UVB exposure effects on heart rate, with dose dependent reductions at 50 hpf, and at 60 hpf for UVA only. The UVB exposure caused an increasing trend in reactive oxygen species (ROS) formation at the two highest doses, even though only significant at 120 hpf for the second highest dose. Both UVA and UVB caused an increasing trend in lipid peroxidation (LPO) at the highest doses tested at 72 hpf. Furthermore, UVA exposure led to significant reductions in larval movement following exposure to the two highest doses of UVA, i.e., reduction in the time spent active and the total distance moved compared to control at 100 hpf, while no effect on the swimming speed was observed. The lowest dose of UVA had no effect on behaviour. In contrast, the highest dose of UVB led to a possible increase in the time spent active and a slower average swimming speed although these effects were not significant (p = 0.07). The obtained results show that UV doses below LD levels are able to cause changes in the behaviour and physiological parameters of zebrafish larvae, as well as oxidative stress in the form of ROS formation and LPO. Further testing is necessary to assess how this type of radiation and the effects observed could affect fish population dynamics.
环境中的紫外线辐射，如果是气候变化的可能后果，其剂量足以对不同的生物体产生影响，其结果取决于暴露的生命阶段。本项目的目的是评估亚致死剂量和环境相关剂量的 UVA（9.4、18.7、37.7 J/cm）和 UVB 辐射（0.013、0.025、0.076 J/cm）对斑马鱼（Danio rerio）早期生命阶段（受精后 4.5-5.5 小时，hpf）发育和行为的潜在毒性影响。使用的剂量均低于半数致死剂量（LD），并且在暴露组和对照组之间，在存活率、畸形或孵化率方面没有显著差异。与对照组相比，UVA 和 UVB 暴露对心率有短暂的影响，在 50 hpf 时，剂量依赖性降低，仅在 UVA 时在 60 hpf 时降低。UVB 暴露在两个最高剂量下导致活性氧（ROS）形成呈上升趋势，尽管在第二个最高剂量下仅在 120 hpf 时才具有统计学意义。UVA 和 UVB 均在最高剂量下导致脂质过氧化（LPO）呈上升趋势，在 72 hpf 时测试的最高剂量下。此外，UVA 暴露导致暴露于两个最高剂量的 UVA 后幼虫运动显著减少，即与对照组相比，100 hpf 时活跃时间减少，总移动距离减少，而游泳速度没有观察到影响。UVA 的最低剂量对行为没有影响。相比之下，UVB 的最高剂量可能导致活跃时间增加，平均游泳速度变慢，尽管这些影响没有统计学意义（p=0.07）。所得结果表明，LD 水平以下的 UV 剂量能够引起斑马鱼幼虫行为和生理参数的变化，以及 ROS 形成和 LPO 形式的氧化应激。需要进一步测试以评估这种类型的辐射和观察到的影响如何影响鱼类种群动态。
