Ifremer, Laboratoire Phycotoxines, Centre Atlantique, 44311 Nantes Cedex, France.
Toxicon. 2013 Dec 1;75:16-26. doi: 10.1016/j.toxicon.2013.05.001. Epub 2013 May 30.
Following a review of official control data on shellfish in France, Ingril Lagoon had been identified as a site where positive mouse bioassays for lipophilic toxins had been repeatedly observed. These unexplained mouse bioassays, also called atypical toxicity, coincided with an absence of regulated toxins and rapid death times in mice observed in the assay. The present study describes pinnatoxin G as the main compound responsible for the toxicity observed using the mouse bioassay for lipophilic toxins. Using a well-characterised standard for pinnatoxin G, LC-MS/MS analysis of mussel samples collected from 2009 to 2012 revealed regular occurrences of pinnatoxin G at levels sufficient to account for the toxicity in the mouse bioassays. Baseline levels of pinnatoxin G from May to October usually exceeded 40 μg kg(-1) in whole flesh, with a maximum in September 2010 of around 1200 μg kg(-1). These concentrations were much greater than those at the other 10 sites selected for vigilance testing, where concentrations did not exceed 10 μg kg(-1) in a 3-month survey from April to July 2010, and where rapid mouse deaths were not typically observed. Mussels were always more contaminated than clams, confirming that mussel is a good sentinel species for pinnatoxins. Profiles in mussels and clams were similar, with the concentration of pinnatoxin A less than 2% that of pinnatoxin G, and pteriatoxins were only present in non-quantifiable traces. Esters of pinnatoxin G could not be detected by analysis of extracts before and after alkaline hydrolysis. Analysis with a receptor-binding assay showed that natural pinnatoxin G was similarly active on the nicotinic acetylcholine receptor as chemically synthesized pinnatoxin G. Culture of Vulcanodinium rugosum, previously isolated from Ingril lagoon, confirmed that this alga is a pinnatoxin G producer (4.7 pg cell(-1)). Absence of this organism from the water column during prolonged periods of shellfish contamination and the dominance of non-motile life stages of V. rugosum both suggest that further studies will be required to fully describe the ecology of this organism and the accumulation of pinnatoxins in shellfish.
在对法国贝类的官方监测数据进行审查后，发现英吉利拉戈恩湾是一个脂溶性贝类毒素阳性小鼠生物测定结果反复出现的地点。这些无法解释的小鼠生物测定结果，也称为非典型毒性，与监测到的实验中无监管毒素和小鼠快速死亡时间一致。本研究描述了齿螺毒素 G 是导致使用脂溶性贝类毒素小鼠生物测定观察到的毒性的主要化合物。使用齿螺毒素 G 的特征明确的标准品，对 2009 年至 2012 年采集的贻贝样本进行 LC-MS/MS 分析显示，齿螺毒素 G 的水平经常出现，足以解释小鼠生物测定中的毒性。5 月至 10 月，整个贻贝肉中的齿螺毒素 G 基线水平通常超过 40μg/kg，2010 年 9 月最高值约为 1200μg/kg。这些浓度远高于其他 10 个选择进行警戒性测试的地点，在 2010 年 4 月至 7 月为期 3 个月的调查中，这些地点的浓度从未超过 10μg/kg，也没有典型的快速小鼠死亡。贻贝的污染程度总是高于蛤，这证实贻贝是齿螺毒素的良好监测物种。贻贝和蛤中的浓度相似，齿螺毒素 A 的浓度不到齿螺毒素 G 的 2%，而 pteriatoxins 仅以无法定量的痕迹存在。在碱性水解前后对提取物进行分析，未能检测到齿螺毒素 G 的酯。用受体结合测定法分析表明，天然齿螺毒素 G 对烟碱型乙酰胆碱受体的活性与化学合成的齿螺毒素 G 相似。从英吉利拉戈恩湾分离出的 Vulcanodinium rugosum 的培养证实，这种藻类是齿螺毒素 G 的生产者（4.7pg 细胞(-1)）。在贝类受污染的长时间内，该生物在水柱中不存在，并且 V. rugosum 的非运动生活阶段占主导地位，这表明需要进一步研究来充分描述该生物的生态学及其在贝类中的积累。
