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
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
Externí odkaz: