Department of Marine Biology, Faculty of Marine Science, Khorramshahr University of Marine Science and Technology, Khorramshahr, Iran.
Environ Toxicol. 2014 Apr;29(4):459-65. doi: 10.1002/tox.21772. Epub 2012 Mar 20.
Nonylphenol (NP) is an endocrine disrupting chemical which has been shown to be able to modulate the endocrine system of various organisms by different mechanisms. The objective of this study was to investigate the potential effects of 4-NP on steroid and thyroid hormone levels in sexually immature male yellowfin seabream (Acanthopagrus latus), a protandrous hermaphrodite species. For this, the fish were injected with ascending doses (10, 50, 100, and 200 μg g(-1) body weight) of 4-nonylphenol (4-NP) or vehicle during 2 weeks. After 7 and 14 days the fish were anesthetized, blood sample were collected and plasma steroid and thyroid hormone concentrations were quantified by radioimmunoassay. The result showed that 4-NP induced a significant increase in 17β-etradiol levels at dose 10 μg g(-1) , while the levels of this hormone in the higher doses decreased compared with the control group. However, 4-NP treatment did not have any significant effect on plasma levels of testosterone. In addition, it was observed that 4-NP affect the level of thyroid hormones in fish. Plasma thyroxine levels increased in a dose-dependent manner after 7 and 14 days of the exposure. In contrast, a significant decrease in triiodothyronine levels was observed during the experiment period. Moreover, no significant change was detected for thyroid stimulating hormone levels in 4-NP-treated fish. These results indicated that 4-NP could lead to disturb the balance of steroid and thyroid hormones with potential consequences for sexually immature male yellowfin seabream.
壬基酚（NP）是一种内分泌干扰化学物质，已被证明能够通过不同的机制调节各种生物体的内分泌系统。本研究的目的是研究 4-NP 对性未成熟雄性黄鳍鲷（Acanthopagrus latus）类固醇和甲状腺激素水平的潜在影响，黄鳍鲷是一种雄性先熟的雌雄同体物种。为此，将鱼用不同剂量（10、50、100 和 200 μg g(-1) 体重）的 4-壬基酚（4-NP）或载体连续注射 2 周。7 天和 14 天后，将鱼麻醉，采集血液样本，并通过放射免疫测定法定量测定血浆类固醇和甲状腺激素浓度。结果表明，4-NP 在 10 μg g(-1) 剂量下诱导 17β-雌二醇水平显著增加，而在较高剂量下，与对照组相比，该激素水平下降。然而，4-NP 处理对血浆睾酮水平没有任何显著影响。此外，还观察到 4-NP 影响鱼类甲状腺激素水平。暴露 7 天和 14 天后，血浆甲状腺素水平呈剂量依赖性增加。相反，在实验期间观察到三碘甲状腺原氨酸水平显著下降。此外，在 4-NP 处理的鱼中，促甲状腺激素水平没有检测到显著变化。这些结果表明，4-NP 可能导致类固醇和甲状腺激素平衡失调，对性未成熟雄性黄鳍鲷产生潜在影响。
