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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。
The toxic LD50 of T-2 toxin was assayed by model fitting method and the activity of Ca2 + -ATPase and polyphenol oxidase (PPO) was analyzed by T-2 toxin poisoning bait. And histopathological changes of muscle, and then to explore the T-2 toxin Litopenaeus vannamei acute toxicity. The results showed that the LD50 of acute toxicity of T-2 to P. vannamei was 1.22 mg / (kg · bw), and the acute toxicity of T-2 to PPO and Ca2 + -ATPase activity was ED50 0.05 and 3.22 mg / (kg · bw), respectively. Comparing with risk assessment index (RI), PPO activity could be used as a biomarker to describe the acute toxicity effect of T-2 to shrimp and more sensitive than Ca2 + -ATPase. Acute exposure of T-2 toxin can lead to an increase in the area ratio of myofibers, leading to deterioration of muscle quality in shrimp. Quantitative detection of T-2 toxin in shrimp muscle by LC-MS / MS, but no residual T-2 toxin was found, indicating that acute exposure of T-2 toxin in shrimps did not lead to material accumulation but resulted in functional accumulation, It may be that T-2 toxin exists in a hidden state, resulting in a gradual accumulation of initial minor lesions.