Abstract

The 17 alpha methyltestosterone (MT) hormone is fed to Oreochromis niloticus larvae in fish farms with the purpose of inducing sex reversal. The aim of this study was to evaluate the toxicity and sub-lethality of MT (99.9% purity) and cMT (a commercial MT with 90% purity) in zebrafish (Danio rerio) adults, where the animals were exposed to concentrations of 0, 4, 23, 139, 833 and 5000 µg/L for 96 hours. Genotoxicity was evaluated by micronucleus test (MN), nuclear abnormalities (NA) and comet assay. A low genotoxic potential of MT was showed, inducing micronucleus, nuclear abnormalities and DNA damage in Danio rerio, depending on the use of MT or cMT, gender and tested concentrations. In the sub-lethality trials, there was a basal difference in the activity of the enzymatic biochemical markers for males and females, while the Glutatione S transferase (GST) activity decreased in all analyzed tissues, and for males the enzymatic activity decreased only in the intestine. Results suggest that MT has a toxic potential to fish because it alters enzymatic metabolic pathways and may pose a risk to the ecosystems.

摘要

将17α甲基睾丸激素（MT）激素喂给养鱼场中的尼罗罗非鱼（Oreochromis niloticus）幼虫，目的是诱导性逆转。这项研究的目的是评估斑马鱼（Danio rerio）成年动物MT（99.9％纯度）和cMT（纯度90％的商业MT）的毒性和亚致死性，这些动物的浓度为0， 4，23，139，833和5000 µg / L，持续96小时。通过微核试验（MN），核异常（NA）和彗星试验评估了遗传毒性。结果表明，MT的遗传毒性很低，可诱导丹尼奥里氏菌产生微核，核异常和DNA损伤。，具体取决于MT或cMT的使用，性别和测试浓度。在亚致死性试验中，男性和女性的酶生化标记物的活性存在基础差异，而所有分析组织中的谷胱甘肽S转移酶（GST）活性均降低，而男性的酶活性仅在男性中降低。肠。结果表明MT对鱼类具有潜在的毒性，因为它会改变酶促代谢途径，并可能对生态系统构成风险。