Cazenave Jimena, Wunderlin Daniel Alberto, de Los Angeles Bistoni María, Amé María Valeria, Krause Eberhard, Pflugmacher Stephan, Wiegand Claudia
Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Cátedra Diversidad Animal II, Velez Sarsfield 299, 5000 Córdoba, Argentina.
Aquat Toxicol. 2005 Oct 15;75(2):178-90. doi: 10.1016/j.aquatox.2005.08.002.
The uptake and accumulation of microcystin-RR (MC-RR) in fish was investigated under laboratory conditions and in wild fish. Jenynsia multidentata and Corydoras paleatus were exposed for 24h to 50mug/L MC-RR dissolved in water. After exposure, liver, gill, brain, intestine, gall bladder, blood and muscle were analyzed for MC-RR by HPLC and analysis confirmed by LC-ESI-TOF-MS spectrometry. Furthermore, wild individuals of Odontesthes bonariensis were sampled from the eutrophic, cyanobacteria-containing San Roque reservoir, and analyzed for the presence of MC-RR in liver, gill, intestine, and muscle. MC-RR was found in liver, gills, and muscle of all exposed and wild fish, while in C. paleatus MC-RR was also present in the intestine. Moreover, we found presence of MC-RR in brain of J. multidentata. Results indicate that MC-RR uptake might occur at two different organs: intestine and gills, through either feeding (including drinking) or respiratory activities. This suggests that MC-RR is taken into the blood stream after absorption, and distributed to different tissues. The liver showed the major bioaccumulation of MC-RR in both experimentally exposed and wild individuals, with muscle of wild fish showing relative high amounts of this toxin in comparison with those exposed in the laboratory; though MC-RR was present in muscle of fish exposed for 24h. The amount of MC-RR in muscle of O. bonariensis exceeded the value suggested by WHO to be safe, thus causing a health risk to persons consuming fish as a result of chronic exposure to microcystin. Gills also showed bioaccumulation of MC-RR, raising questions on the mechanism involved in the possible uptake of MC-RR through gills as well as on its accumulation in this organ. Although MC-LR has been reported in brain of fish, this is the first report confirming the presence of MC-RR in this organ, which means that both toxins are able to cross the blood-brain barrier. These findings also raise questions on the probable neurotoxicity of microcystins.
在实验室条件下以及对野生鱼类进行了微囊藻毒素-RR（MC-RR）在鱼类体内摄取和积累的研究。将多齿珍妮丽鱼和巴氏兵鲶暴露于溶解在水中的50μg/L MC-RR中24小时。暴露后，通过高效液相色谱法（HPLC）对肝脏、鳃、脑、肠道、胆囊、血液和肌肉中的MC-RR进行分析，并通过液相色谱-电喷雾离子化-飞行时间质谱法（LC-ESI-TOF-MS）进行确认。此外，从富营养化的、含有蓝藻的圣罗克水库采集了野生长臂银汉鱼个体，分析其肝脏、鳃、肠道和肌肉中MC-RR的存在情况。在所有暴露的和野生的鱼类的肝脏、鳃和肌肉中均发现了MC-RR，而在巴氏兵鲶的肠道中也存在MC-RR。此外，我们在多齿珍妮丽鱼的脑中发现了MC-RR的存在。结果表明，MC-RR的摄取可能发生在两个不同的器官：肠道和鳃，通过摄食（包括饮水）或呼吸活动。这表明MC-RR在吸收后进入血流，并分布到不同组织。在实验暴露的个体和野生个体中，肝脏均显示出MC-RR的主要生物积累，与实验室暴露的鱼类相比，野生鱼类的肌肉中该毒素含量相对较高；尽管在暴露24小时的鱼类肌肉中也存在MC-RR。长臂银汉鱼肌肉中的MC-RR含量超过了世界卫生组织建议的安全值，因此由于长期接触微囊藻毒素，食用鱼类会给人类健康带来风险。鳃也显示出MC-RR的生物积累，这引发了关于通过鳃摄取MC-RR的可能机制以及其在该器官中积累的问题。虽然已报道鱼类脑中存在微囊藻毒素-LR（MC-LR），但这是首次证实该器官中存在MC-RR的报告，这意味着两种毒素都能够穿过血脑屏障。这些发现也引发了关于微囊藻毒素可能的神经毒性的问题。
