Levonorgestrel exposure to fathead minnows (Pimephales promelas) alters survival, growth, steroidogenic gene expression and hormone production

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• 作者：Matthew D. Overturf ; Carmen L. Overturf ; Dennis R. Carty ; David Hala ; Duane B. Huggett
• 关键词：Early-life Stage ; Fish ; Endocrine ; Levonorgestrel
• 刊名：Aquatic Toxicology
• 出版年：March, 2014
• 年：2014
• 卷：148
• 期：Complete
• 页码：152-161
• 全文大小：1433 K

文摘

Human pharmaceuticals are commonly detected in the environment. Concern over these compounds in the environment center around the potential for pharmaceuticals to interfere with the endocrine system of aquatic organisms. The main focus of endocrine disruption research has centered on how estrogenic and androgenic compounds interact with the endocrine system to elicit reproductive effects. Other classes of compounds, such as progestins, have been overlooked. Recently, studies have investigated the potential for synthetic progestins to impair reproduction and growth in aquatic organisms. The present study utilizes the OECD 210 Early-life Stage (ELS) study to investigate the impacts levonorgestrel (LNG), a synthetic progestin, on fathead minnow (FHM) survival and growth. After 28 days post-hatch, survival of larval FHM was impacted at 462 ng/L, while growth was significantly reduced at 86.9 ng/L. Further analysis was conducted by measuring specific endocrine related mRNA transcript profiles in FHM larvae following the 28 day ELS exposure to LNG. Transcripts of 3尾-HSD, 20尾-HSD, CYP17, AR, ER伪, and FSH were significantly down-regulated following 28 d exposure to 16.3 ng/L LNG, while exposure to 86.9 ng/L significantly down-regulated 3尾-HSD, 20尾-HSD, CYP19A, and FSH. At 2392 ng/L of LNG, a significant down-regulation occurred with CYP19A and ER尾 transcripts, while mPR伪 and mPR尾 profiles were significantly induced. No significant changes occurred in 11尾-HSD, CYP11A, StAR, LH尾, and VTG mRNA expression following LNG exposure. An ex vivo steroidogenesis assay was conducted with sexually mature female FHM following a 7 day exposure 100 ng/L LNG with significant reductions observed in pregnenolone, 17伪,20尾-dihydroxy-4-pregnen-3-one (17,20-DHP), testosterone, and 11-ketotestosterone. Together these data suggest LNG can negatively impact FHM larval survival and growth, with significant alterations in endocrine related responses.