title: Effects of prochloraz or propylthiouracil on the cross-talk between the HPG, HPA, and HPT axes in zebrafish.
abstract: The objective of this study was to assess chemical-induced effects on cross-talk among the hypothalamic-pituitary-gonad (HPG), hypothalamic-pituitary-adrenal (HPA), and hypothalamic-pituitary-thyroid (HPT) axes of fish. Adult female zebrafish were exposed to 300 μg/L prochloraz (PCZ) or 100 mg/L propylthiouracil (PTU), and the transcriptional profiles of the HPG, HPA, and HPT axes were examined. Exposure to PCZ decreased plasma testosterone (T) and 17β-estradiol (E2) concentrations and affected HPA and HPT axes by down-regulating corticotrophin-releasing hormone (CRH) after 12 and 48 h. By using correlation analyses, it was found that the decrease in E2 plasma concentrations caused by PCZ was correlated with the down-regulation of CRH mRNA expression. Exposure to PTU resulted in lesser concentrations of thyroxine (T4) and triiodothyronine (T3), greater concentrations of follicle stimulating hormone (FSH) and luteinizing hormone (LH) peptides, and increase in steroidogenic gene expression after 12 and 48 h. Concentrations of FSH and LH were negatively correlated with concentrations of T4 and T3. These results are consistent with the hypothesis that increased steroidogenic gene expression after PTU exposure resulted from a reduction in T4 and T3 concentrations, which resulted in greater secretion of FSH and LH.
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.
authors.forename: Chunsheng
authors.initials: C
authors.lastname: Liu
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Zhang
authors.forename: Jun
authors.initials: J
authors.lastname: Deng
authors.forename: Markus
authors.initials: M
authors.lastname: Hecker
authors.forename: Abdulaziz
authors.initials: A
authors.lastname: Al-Khedhairy
authors.forename: John P
authors.initials: JP
authors.lastname: Giesy
authors.forename: Bingsheng
authors.initials: B
authors.lastname: Zhou
mesh_terms: D000311:Adrenal Glands / Q000187:drug effects; D000818:Animals; D003346:Corticotropin-Releasing Hormone / Q000097:blood / Q000378:metabolism; D004958:Estradiol / Q000097:blood / Q000235:genetics / Q000378:metabolism; D005260:Female; D006066:Gonads / Q000187:drug effects; D007031:Hypothalamus / Q000187:drug effects; D007093:Imidazoles / Q000633:toxicity*; D010902:Pituitary Gland / Q000187:drug effects; D011441:Propylthiouracil / Q000633:toxicity*; D012333:RNA, Messenger / Q000378:metabolism; D020239:Receptor Cross-Talk / Q000187:drug effects*; D013739:Testosterone / Q000097:blood / Q000378:metabolism; D013961:Thyroid Gland / Q000187:drug effects; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015027:Zebrafish / Q000378:metabolism*
chemical_list: D007093:Imidazoles; D012333:RNA, Messenger; D014874:Water Pollutants, Chemical; D013739:Testosterone; D004958:Estradiol; D011441:Propylthiouracil; D003346:Corticotropin-Releasing Hormone; C045362:prochloraz