Single and combined exposure of microcystin-LR and nitrite results in reproductive endocrine disruption via hypothalamic-pituitary-gonadal-liver axis
Autor: | Dandan Zhang, Li Li, Xueyang Wu, Lingkai Wang, Wang Lin, Honghui Guo, Dapeng Li, Xuezhen Zhang, Yufen Li, Jie Hou |
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Rok vydání: | 2018 |
Předmět: |
Male
0301 basic medicine medicine.medical_specialty Microcystis Environmental Engineering Gonad Microcystins Health Toxicology and Mutagenesis Population Endocrine System Hypothalamic–pituitary–gonadal axis Fish reproduction Endocrine Disruptors 010501 environmental sciences Biology 01 natural sciences 03 medical and health sciences chemistry.chemical_compound Internal medicine Testis medicine Animals Environmental Chemistry Endocrine system Enzyme Inhibitors Nitrite Gonads education Nitrites Zebrafish 0105 earth and related environmental sciences education.field_of_study Reproduction Public Health Environmental and Occupational Health Drug Synergism General Medicine General Chemistry Pollution 030104 developmental biology Endocrinology medicine.anatomical_structure Gene Expression Regulation chemistry Marine Toxins Growth inhibition Reproductive toxicity Water Pollutants Chemical |
Zdroj: | Chemosphere. 211:1137-1146 |
ISSN: | 0045-6535 |
Popis: | Microcystin-LR (MC-LR) released by Microcystis blooms degradation usually co-exists with a chemical called nitrite, posing a serious harm to aquatic organisms. To assess the single and combined effects of MC-LR and nitrite on the reproductive endocrine system, a fully factorial experiment was designed and adult male zebrafish (Danio rerio) were exposed to 9 treatment combinations of MC-LR (0, 3, 30 μg/L) and nitrite (0, 2, 20 mg/L) for 30 d. The results showed that both MC-LR and nitrite caused concentration-dependent effects including the growth inhibition, decreased gonad index as well as testicular injuries with widen intercellular spaces and seminiferous epithelium deteriorations. And testicular pathological changes in the co-exposure groups of MC-LR and nitrite were similar but more serious than those in single-factor exposure groups. Concurrently, exposure to MC-LR or nitrite alone could significantly decrease T levels by downregulating gene expressions (gnrh2, lhβ, ar, lhr) in the hypothalamic-pituitary-gonadal-liver-axis (HPGL-axis), and there were significant interactions between MC-LR and nitrite on them. In contrast, E2 levels as well as transcriptional levels of cyp19a1b, cyp19a1a and vtg1 showed significant inductions with increasing MC-LR concentrations, indicating an estrogen-like effect of MC-LR. Our findings illustrated that co-exposure of MC-LR and nitrite synergistically cause reproductive dysfunction by interfering with the HPGL axis in male fish, which prompt us to focus more on the potential risks in fish reproduction and even population dynamics due to the wide occurrence of toxic cyanobacterial blooms. |
Databáze: | OpenAIRE |
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