Kopp Radovan, Mares Jan, Soukupova Zdenka, Navratil Stanislav, Palikova Miroslava
Neuro Endocrinol Lett. 2014;35 Suppl 2:57-63.
Fish can be exposed under environmental conditions to multiple stressors including natural toxins and environmental or feed contamination at the same time. This study brings new knowledge about the effects of controlled exposure to multiple stressors in fish. The aim of this study was to test the hypothesis that influence of cyanobacterial biomass and arsenic in feed can combine to enhance the effects on fish.
Rainbow trouts were sorted into six groups, each with 25 specimens: control group (fed with commercial feed), groups exposed to toxic cyanobacterial biomass (81 mg x kg(-1) MCs of feed), two groups exposed to arsenic (concentration of 5 mg x kg(-1), and 50 mg x kg(-1) of fish feed) and two groups exposed to combination of cyanobacterial biomass and arsenic in two concentrations mentioned above. The experiment lasted 30 days. During the experiment we evaluated the influence of co-exposure on plasmatic parameters mentioned above. Samples were collected on days 10, 20 and 30 of exposure.
Biochemical analysis revealed a significant decrease in calcium (T20) and an increase in natrium (T10) and chlorides (T10) values in combined cyanobacterial and arsenic exposures. Our results showed a significant decrease in the values of magnesium after exposure to higher concentration of arsenic compared to control and feeding with addition of cyanobacterial biomass groups. The changes of other monitored plasmatic parameters were not significantly increased or decreased in comparison with controls.
Our results confirmed the hypothesis that influence of toxic cyanobacterial biomass and a chemical agent represented by arsenic can combine to enhance the effects on fish. This work originally shows that while the single agents in sub-lethal doses do not cause changes in the plasmatic parameters, their co-exposure leads to the significantly decrease or increase of the electrolytes of rainbow trout.
鱼类在环境条件下可能同时受到多种应激源的影响，包括天然毒素以及环境或饲料污染。本研究带来了关于鱼类受控暴露于多种应激源影响的新知识。本研究的目的是检验以下假设：饲料中蓝藻生物量和砷的影响可共同增强对鱼类的作用。
虹鳟鱼被分为六组，每组25条样本：对照组（投喂商业饲料）、暴露于有毒蓝藻生物量的组（饲料中微囊藻毒素含量为81毫克/千克）、两组暴露于砷的组（鱼饲料中砷浓度分别为5毫克/千克和50毫克/千克）以及两组暴露于上述两种浓度蓝藻生物量和砷组合的组。实验持续30天。在实验期间，我们评估了共同暴露对上述血浆参数的影响。在暴露的第10天、20天和30天采集样本。
生化分析显示，在蓝藻和砷联合暴露组中，钙含量显著降低（第20天），钠（第10天）和氯（第10天）含量增加。我们的结果表明，与对照组和添加蓝藻生物量饲料组相比，暴露于较高浓度砷后，镁含量显著降低。与对照组相比，其他监测的血浆参数变化未显著增加或减少。
我们的结果证实了以下假设：有毒蓝藻生物量的影响与以砷为代表的化学物质的影响可共同增强对鱼类的作用。这项工作最初表明，虽然亚致死剂量的单一因素不会导致血浆参数变化，但它们的共同暴露会导致虹鳟鱼电解质显著降低或增加。
