中文摘要：

通过T-2毒素微胶囊毒饵料一次性染毒凡纳滨对虾,采用模型拟合法测定T-2毒素对凡纳滨对虾经口LD50,并分析Ca2＋-ATPase、多酚氧化酶（PPO）活力以及肌肉病理组织学变化,进而探明T-2毒素对凡纳滨对虾急性毒性效应。结果表明,T-2毒素对凡纳滨对虾的急性毒性经口一次性暴露的LD50为1.22 mg/（kg·bw）,T-2毒素对PPO酶活性和Ca2＋-ATPase活性的急性毒性效应ED50分别为0.05和3.22 mg/（kg·bw）,比较风险评估指数RI可知,PPO活性可作为生物学效应标记描述T-2毒素对对虾的急性毒性效应,且比Ca2＋-ATPase更加灵敏。T-2毒素急性暴露可导致肌纤维间隙面积比增大,可导致对虾肌肉品质劣化。采用LC-MS/MS定量检测染毒对虾肌肉中的T-2毒素,但是没有发现游离态T-2毒素残留,说明对虾中T-2毒素急性暴露不会引起物质蓄积,但却产生功能蓄积,可能是T-2毒素以隐蔽态形式存在,导致初始轻微损伤逐渐累加的结果。

英文摘要：

Litopenaeus vannamei were orally administered as single-dose capsules containing the T-2 toxin （T-2）, and the oral median lethal dose （LD50） of the T-2 toxin in Litopenaeus vannamei was determined using the model-fitting method. The Ca2＋-ATPase and polyphenol oxidase （PPO） activities, as well as the histopathological changes in muscles were analyzed to explore the acute toxicity of T-2 on Litopenaeus vannamei. The results showed that the LD50 of T-2 via oral administration in a single dose was 1.22 mg/（kg.bw）, and the medium effective dose （ED50） levels of Ca2＋-ATPase and PPO activities were 0.05 and 3.22 mg/（kg.bw）, respectively. According to the risk index （RI）, the PPO activity can serve as a biological marker for the acute toxicity of T-2 on Litopenaeus vannamei and is more sensitive than Ca2＋-ATPase. Acute T-2 exposure could lead to an increasing area ratio of the muscle fiber gap and shrimp quality deterioration. Quantitative analysis of T-2 in shrimp muscles was conducted by liquid chromatography-tandem mass spectrometry （LC-MS/MS）; no free T-2 residues were found, indicating that acute T-2 exposure in shrimp could cause functional accumulation but not material accumulation. This was probably because T-2 was present in a masked form, which led to the gradual accumulation of minor damage during the initial stage.