Adamovsky Ondrej, Kopp Radovan, Zikova Andrea, Blaha Ludek, Kohoutek Jiri, Ondrackova Petra, Paskerova Hana, Mares Jan, Palikova Miloslava
Research Centre for Toxic Compounds in the Environment (RECETOX), Masaryk University - Faculty of Science Brno, Czech Republic.
Neuro Endocrinol Lett. 2011;32 Suppl 1:35-45.
The toxic cyanobacteria are a serious problem for water supply systems, recreation, and agriculture. Cyanobacteria produce numerous bioactive compounds including microcystins - the most studied cyanobacterial hepatotoxins. Only rare studies addressed realistic situation, i.e. impact of MCs accumulated in the fish tissues on the overall physiology. The aim of the present study was to provide a model simulation of the simple food chain for evaluation of impacts of cyanobacteria on the rat physiology under different exposure scenario.
Experimental rats were fed with food with fish meat, which contained external additions of isolated microcystins as well as toxic cyanobacteria Microcystis, nontoxic cyanobacteria Arthrospira and green alga Chlorella. Subgroups of the animals were also challenged with a model antigen KLH to investigated immune-related parameters. We studied parameters of oxidative stress in the liver as levels of lipid peroxidation and glutathion levels. Series of hematological, biochemical and immunological parameters were also investigated.
Although considerable amounts of microcystins were administered to rats, all levels of MCs were under the detection limit (1 ng/g fresh weight) in the rat tissues using tandem LC/MS. Only some conjugates of microcystins with cystein and glutathion were detected in the rat liver exposed to Microcystis biomass (values were around the detection limit). Statistically significant depletion of body and liver weight was observed in groups with microcystin addition in comparison with all other groups. Rats exposed to MCs had stimulated immune system (showed higher antibody answer on administered antigen). Also modulation of some lymphocyte subpopulations was recorded with the most interesting observation of stimulated NK cell numbers in groups exposed to isolated toxins (but not to biomass containing the same toxin amount).
Our study demonstrates that oral exposure to microcystins in the diet may induce some detoxification responses and modulation of some hematological and immunological parameters.
有毒蓝藻对供水系统、娱乐和农业构成严重问题。蓝藻产生多种生物活性化合物，包括微囊藻毒素——研究最多的蓝藻肝毒素。仅有少数研究涉及实际情况，即鱼类组织中积累的微囊藻毒素对整体生理的影响。本研究的目的是提供一个简单食物链的模型模拟，以评估在不同暴露情况下蓝藻对大鼠生理的影响。
给实验大鼠喂食含有鱼肉的食物，鱼肉中额外添加了分离出的微囊藻毒素以及有毒蓝藻微囊藻、无毒蓝藻节旋藻和绿藻小球藻。还对动物亚组用模型抗原钥孔戚血蓝蛋白进行刺激，以研究免疫相关参数。我们研究了肝脏中氧化应激参数，如脂质过氧化水平和谷胱甘肽水平。还研究了一系列血液学、生物化学和免疫学参数。
尽管给大鼠投喂了大量微囊藻毒素，但使用串联液相色谱/质谱法在大鼠组织中所有微囊藻毒素水平均低于检测限（1纳克/克鲜重）。仅在暴露于微囊藻生物量的大鼠肝脏中检测到一些微囊藻毒素与半胱氨酸和谷胱甘肽的结合物（数值约为检测限）。与所有其他组相比，添加微囊藻毒素的组中观察到体重和肝脏重量有统计学意义的减少。暴露于微囊藻毒素的大鼠免疫系统受到刺激（对给予的抗原显示出更高的抗体反应）。还记录到一些淋巴细胞亚群的调节，最有趣的观察结果是暴露于分离毒素的组中自然杀伤细胞数量增加（但暴露于含相同毒素量生物量的组中未出现）。
我们的研究表明，饮食中口服微囊藻毒素可能诱导一些解毒反应以及对一些血液学和免疫学参数的调节。
