Lance Emilie, Petit Anais, Sanchez Wilfried, Paty Christelle, Gérard Claudia, Bormans Myriam
Unité de Recherche Interactions Animal-Environnement, EA 4689, Bat 18, Campus du Moulin de la Housse, BP 1039, 51687 REIMS Cedex 2, France.
UMR CNRS 6553, University of Rennes 1, 263 Avenue du Général Leclerc, CS 74205, 35042 Rennes Cedex, France.
Harmful Algae. 2014 Jan;31:9-17. doi: 10.1016/j.hal.2013.09.006. Epub 2013 Oct 6.
According to our previous results the gastropod Lymnaea stagnalis exposed to MC-producing cyanobacteria accumulates microcystins (MCs) both as free and covalently bound forms in its tissues, therefore representing a potential risk of MC transfer through the food web. This study demonstrates in a laboratory experiment the transfer of free and bound MCs from L. stagnalis intoxicated by MC-producing Planktothrix agardhii ingestion to the fish Gasterosteus aculeatus. Fish were fed during five days with digestive glands of L. stagnalis containing various concentrations of free and bound MCs, then with toxin-free digestive glands during a 5-day depuration period. MC accumulation was measured in gastropod digestive gland and in various fish organs (liver, muscle, kidney, and gills). The impact on fish was evaluated through detoxification enzyme (glutathion-S-transferase, glutathion peroxydase and superoxyde dismutase) activities, hepatic histopathology, and modifications in gill ventilation, feeding and locomotion. G. aculeatus ingestion rate was similar with intoxicated and toxin-free diet. Fish accumulated MCs (up to 3.96±0.14μggDW) in all organs and in decreasing order in liver, muscle, kidney and gills. Hepatic histopathology was moderate. Glutathion peroxydase was activated in gills during intoxication suggesting a slight reactive oxygen species production, but without any impact on gill ventilation. Intoxication via ingestion of MC-intoxicated snails impacted fish locomotion. Intoxicated fish remained significantly less mobile than controls during the intoxication period possibly due to a lower health condition, whereas they showed a greater mobility during the depuration period that might be related to an acute foraging for food. During depuration, MC elimination was total in gills and kidney, but partial in liver and muscle. Our results assess the MC transfer from gastropods to fish and the potential risk induced by bound MCs in the food web.
根据我们之前的研究结果，暴露于产微囊藻毒素蓝藻的腹足纲动物静水椎实螺，会在其组织中以游离和共价结合形式积累微囊藻毒素（MCs），因此代表了通过食物网转移MCs的潜在风险。本研究在实验室实验中证明了，游离和结合态的MCs从因摄食产MCs的阿氏浮丝藻而中毒的静水椎实螺，转移到了三刺鱼。在五天时间里，给鱼投喂含有不同浓度游离和结合态MCs的静水椎实螺消化腺，然后在为期五天的净化期投喂无毒的消化腺。在腹足纲动物消化腺和各种鱼器官（肝脏、肌肉、肾脏和鳃）中测量MCs的积累情况。通过解毒酶（谷胱甘肽 - S - 转移酶、谷胱甘肽过氧化物酶和超氧化物歧化酶）活性、肝脏组织病理学以及鳃通气、摄食和运动的变化来评估对鱼的影响。三刺鱼对中毒和无毒食物的摄食率相似。鱼在所有器官中都积累了MCs（最高达3.96±0.14μg/g干重），在肝脏、肌肉、肾脏和鳃中的积累量依次降低。肝脏组织病理学变化程度中等。在中毒期间，鳃中的谷胱甘肽过氧化物酶被激活，表明有轻微的活性氧产生，但对鳃通气没有任何影响。通过摄食中毒螺而中毒影响了鱼的运动。在中毒期间，中毒鱼的活动能力明显低于对照组，这可能是由于健康状况较差，而在净化期它们表现出更大的活动能力，这可能与急性觅食有关。在净化期，鳃和肾脏中的MCs完全消除，但肝脏和肌肉中的消除不完全。我们的结果评估了MCs从腹足纲动物向鱼的转移以及食物网中结合态MCs所引发的潜在风险。
