In the present study, we assessed the negative effects of triphenyltin (TPT) on zebrafish (Danio rerio) by exposing embryos and early-stage larvae to various concentrations of TPT from 2 h after fertilization (haf) until 30 days after hatching (dah). Whether test groups were fed or fasted during ecotoxicity studies using fish models has varied historically, and whether this experimental condition influences test results is unknown. Here, we confirmed that the lethal concentration of TPT to embryo and early-stage larvae (i.e., 3 dah or younger) showed in fed (lowest observed effect concentration (LOEC); 6.34 μg/L) and fasted (LOEC; 6.84 μg/L) groups. In addition, 84% and 100% of the larvae in the 2.95 and 6.64 μg/L exposure groups, respectively, had uninflated swim bladders; all affected larvae died within 9 dah. This finding suggests that morphologic abnormalities in early larval zebrafish are useful as endpoints for predicting the lethality of chemical substances after hatching. We then assessed the expression of several genes in the thyroid hormone pathway, which regulates swim bladder development in many fish species, including zebrafish. Larvae exposed to 6.64 μg/L TPT showed significant increases in the mRNA expression levels of thyroid hormone receptor α (trα) and trβ but not of thyroid stimulating hormone β subunit. These findings suggest that TPT disrupts the thyroid system in zebrafish.

在本研究中，我们评估了三苯基锡（TPT）对斑马鱼（Danio rerio），从受精后（hf）到孵化后30天（dah），将胚胎和早期幼虫暴露于不同浓度的TPT中。在使用鱼类模型进行生态毒性研究期间，是否给测试组喂食或禁食在历史上一直存在变化，这种实验条件是否会影响测试结果尚不清楚。在这里，我们证实了饲喂时TPP对胚胎和早期幼虫（即3天以下）的致死浓度（最低观察到的作用浓度（LOEC）； 6.34μg/ L）和禁食（LOEC； 6.84μg/ L）。 L）组。另外，在2.95和6.64μg/ L的暴露组中，分别有84％和100％的幼虫具有未充气的游泳膀胱；所有受影响的幼虫在9天之内死亡。这一发现表明，早期幼虫斑马鱼的形态异常可用作预测孵化后化学物质致死性的终点。然后，我们评估了甲状腺激素途径中几个基因的表达，该途径可调节许多鱼类（包括斑马鱼）的膀胱发育。暴露于6.64μg/ L TPT的幼虫显示甲状腺激素受体α（trα）和trβ，但不包含促甲状腺激素β亚基。这些发现表明TPT破坏了斑马鱼的甲状腺系统。