Acute microcystin-LR exposure interfere thyroid hormones homeostasis in adult zebrafish (Danio rerio). (March 2020)

• Record Type: Journal Article
• Authors: Gao, Yu; Liu, Zidong; Jia, Dan; Hu, Qing; Li, Li; Tang, Rong; Li, Dapeng
• Is Part Of: Chemosphere. Volume 243(2020)
• Publication Date: 2020-03
• Subjects: Microcystin-LR -- Thyroid hormones -- Complement component 9 -- Iodothyronine deiodinases activity; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2019.125258
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Microcystin-LR (MC-LR) in the aquatic environment may disturb thyroid hormone (TH) homeostasis. It is not clear how MC-LR affects downstream biological processes after TH disturbance. After exposure to 50, 100, 200 and 400 μg/L MC-LR for 24, 48, 72, or 96 h, alterations of the TH metabolism of adult zebrafish at thyroxine (T4), triiodothyronine (T3) levels, and iodothyronine deiodinase (Dio) activity, were observed. After exposure to MC-LR at 400 μg/L, T3 and T4 levels decreased significantly in females ( p < 0.05) and returned to normal levels at 96 h. In males, T4 levels were not significantly different between groups. The expression of corticotropin releasing hormone, thyroid-stimulating hormone beta subunit, transthyretin, sodium/iodide cotransporter, thrombopoietin, thyroid hormone receptor alpha and beta changed, but not in a dose-dependent manner. Acute MC-LR exposure induced a negative feedback regulation of the hypothalamic-pituitary-thyroid axis in adult zebrafish, and females were more sensitive than males. In conclusion, acute MC-LR exposure disrupted the TH metabolism by altering Dio activity and gene expression of the HPT axis; these changes may affect the complement system through regulation of c9 mRNA synthesis. Graphical abstract: Image 1 Highlights: Acute MC-LR exposure disrupts thyroid function in zebrafish. Females were more sensitive to MC-LR than males on TH levels and Dio activities. MC-LR may affect C9 mRNA synthesis by affecting TRs.