Abstract：
In recent years, studies have focused on the combined ecological risks posed by microplastics and other organic pollutants. Although both microplastics and progestin residues are frequently detected in the aquatic environments, their ecological implications remain unknown. Adult zebrafish were exposed to polystyrene microplastics (PS, 200 nm, 200 μg/L), norethindrone (NET, 69.6 ng/L), and their mixture (200 μg/L PS + 63.1 ng/L NET) for 30 days. The results demonstrated that exposure to PS and NET resulted in gill damage. Notably, the PS and PS+NET exhibited a significant decrease in glutathione (GSH) and oxidized glutathione (GSSG) content, as well as reduced antioxidase activity in the gills. The oxidative stress in PS+NET primarily originated from PS. The PS, NET, or their mixture resulted in a decrease in testosterone (T) and estradiol (E2) levels in female. Furthermore, compared to NET, the PS+NET showed a significant reduction in E2 levels, thereby augmenting the inhibitory effect on reproductive ability mediated by NET. However, males showed an increase in 11-ketodihydrotestosterone (11-KT) content, accompanied by a significant decrease in spermatogonia (Sg) and increase in spermatocytes (Sc). Consequently, it can be inferred that PS enhances the androgenic effect of NET. In female fish brain, NET alone resulted in transcriptional down-regulation of partial hormone receptors; however, co-administration of PS effectively mitigated the interference effects. Furthermore, transcriptional downregulation of 17-alpha-hydroxylase (cyp17), hydroxysteroid 3-beta dehydrogenase (hsd3b), estrogen receptor 1 (esr1), and estrogen receptor 2a (esr2b) genes in the ovary was found to be associated with the androgenic activity induced by NET. Moreover, in comparison to PS or NET alone, PS+NET resulted in a notable decrease in Cetobacterium abundance and an increase in Aeromonas population, suggesting that the co-exposure of PS+NET may exacerbate intestinal burden. The findings highlight the importance of studying the combined toxicity of PS and NET.
摘要：
近年来,研究集中在微塑料和其他有机污染物带来的综合生态风险上。尽管在水生环境中经常检测到微塑料和孕激素残留物，它们的生态影响仍然未知。成年斑马鱼暴露于聚苯乙烯微塑料(PS，200nm,200μg/L)，noretindrone(NET，69.6纳克/升)，和它们的混合物(200μg/LPS+63.1ng/LNET)持续30天。结果表明，暴露于PS和NET会导致g损伤。值得注意的是,PS和PS+NET显示谷胱甘肽(GSH)和氧化型谷胱甘肽(GSSG)含量显著下降,以及减少的抗氧化酶的活性。PS+NET中的氧化应激主要来源于PS。PS,NET，或它们的混合物导致女性睾酮（T）和雌二醇（E2）水平降低。此外，与NET相比，PS+NET显示E2水平显著降低，从而增强NET介导的对生殖能力的抑制作用。然而,男性显示11-酮二氢睾酮（11-KT）含量增加，伴随着精原细胞（Sg）的显着减少和精母细胞（Sc）的增加。因此,可以推断PS增强了NET的雄性激素效应。在雌性鱼脑中，NET单独导致部分激素受体的转录下调；然而，PS的共同给药有效地减轻了干扰效应。此外，17-α-羟化酶（cyp17）的转录下调，羟基类固醇3-β脱氢酶（hsd3b），雌激素受体1（esr1），发现卵巢中的雌激素受体2a（esr2b）基因与NET诱导的雄激素活性有关。此外，与单独的PS或NET相比，PS+NET导致细菌丰度显着下降，气单胞菌数量增加，这表明PS+NET的共同暴露可能会加剧肠道负担。研究结果强调了研究PS和NET联合毒性的重要性。
