Department of Zoology and Environmental Biology, University of Calabar, Calabar, Nigeria.
Department of Zoology and Environmental Biology, University of Calabar, Calabar, Nigeria; Department of Biology, Norwegian University of Science and Technology (NTNU), Høgskoleringen 5, N-7491 Trondheim, Norway.
Comp Biochem Physiol C Toxicol Pharmacol. 2019 Nov;225:108584. doi: 10.1016/j.cbpc.2019.108584. Epub 2019 Aug 5.
In the present study, we investigated plasma biochemical and steroid hormone responses, together with gonado-histopathological alterations in Clarias gariepinus exposed to sublethal concentrations of two synthetic pyrethroids (cypermethrin and deltamethrin). Fish were exposed to environmentally-relevant concentrations of cypermethrin at 0 (ethanol solvent control), 0.07, 0.014, 0.028, 0.056) and deltamethrin at 0.22, 0.44, 0.88 and 1.76 μg/L, for 7, 14, 21 and 28 days. Plasma enzyme (aspartate transaminase: AST, alanine transaminase: ALT and alkaline phosphatase: ALP) and steroid hormones (estradiol-17β: E2, testosterone: T) levels were analyzed. Gonado-histopathological evaluation shows the presence of ovo-testis (intersex), oocytes atresia, cytoplasmic degeneration and clumping of vitellogenic oocytes in females, while male fish displayed enlargement and degeneration of testicular seminiferous tubules after 28 days exposure to cypermethrin and deltamethrin. Plasma biochemical analysis in pesticides exposed fish revealed that AST, ALT and ALP were significantly increased in a concentration-dependent manner. In addition, we observed respective and apparent concentration- and time-dependent increase and decrease of plasma E2 and T levels, compared to control. Interestingly, the significant increase in E2 levels paralleled gonadal ovo-testis (intersex) condition in exposed fish, indicating endocrine disruptive effects of cypermethrin and deltamethrin that favor the estrogenic pathway, in addition to overt negative consequences on reproductive, biochemical and physiological health of the exposed fish.
在本研究中，我们调查了血浆生化和类固醇激素反应，以及在亚致死浓度下暴露于两种合成拟除虫菊酯（氯菊酯和溴氰菊酯）的蓝鳃太阳鱼的性腺组织病理学变化。鱼暴露于环境相关浓度的氯菊酯在 0（乙醇溶剂对照）、0.07、0.014、0.028、0.056 和溴氰菊酯在 0.22、0.44、0.88 和 1.76μg/L，暴露时间为 7、14、21 和 28 天。分析了血浆酶（天冬氨酸转氨酶：AST、丙氨酸转氨酶：ALT 和碱性磷酸酶：ALP）和类固醇激素（雌二醇-17β：E2、睾酮：T）水平。性腺组织病理学评估显示存在卵睾（雌雄同体）、卵母细胞闭锁、细胞质退化和卵黄生成卵母细胞的聚集，而雄性鱼在暴露于氯菊酯和溴氰菊酯 28 天后显示睾丸精曲小管的增大和退化。暴露于杀虫剂的鱼的血浆生化分析显示，AST、ALT 和 ALP 呈浓度依赖性显著增加。此外，与对照组相比，我们观察到血浆 E2 和 T 水平分别表现出明显的浓度和时间依赖性增加和减少。有趣的是，E2 水平的显著增加与暴露鱼的性腺卵睾（雌雄同体）状况平行，表明氯菊酯和溴氰菊酯具有内分泌干扰作用，有利于雌激素途径，除了对暴露鱼的生殖、生化和生理健康产生明显的负面影响外。
