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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Animal Metabolism-Agricultural Chemicals Research » Research » Publications at this Location » Publication #323274
Title: Modulation of estrogenic exposure effects via alterations in salinity and dissolved oxygen in male fathead minnows, Pimephales promelas

Author
item FEIFAREK, DAVID - St Cloud State University
item REARICK, DANIEL - St Cloud State University
item Shappell, Nancy
item SCHOENFUSS, HEIKO - St Cloud State University

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/29/2015
Publication Date: 11/1/2015
Citation: Feifarek, D.J., Rearick, D.C., Shappell, N.W., Schoenfuss, H.L. 2015. Modulation of estrogenic exposure effects via alterations in salinity and dissolved oxygen in male fathead minnows, Pimephales promelas [abstract]. 36th Annual Society of Environmental and Toxicology and Chemistry. Nov. 1-5, 2015. Salt Lake City, UT. Paper no. RP132.

Interpretive Summary: Laboratory exposure data indicate that estrogens and estrogen mimics can cause endocrine disruption in male fathead minnows (Pimephales promelas). In the wild, conditions are not static as is often the case in the laboratory. Changes in water quality parameters, such as salinity influx due to road salt intrusion and aquatic hypoxia due to cultural eutrophication, can trigger physiological and anatomical changes in fish that have the potential to alter the uptake and observed effects of estrogenic chemicals. To explore the role of environmental variables on the expression of biomarkers of estrogenic exposure, adult male P. promelas were exposed to estrone (E1) under various chloride and dissolved oxygen conditions in the laboratory for 21 days in a flow-through system. Plasma vitellogenin (VTG), morphological characteristics, hematological parameters, and histopathology were assessed to determine the severity of estrogenic effect. Salinity at 50 PPM added NaCl had no significant effect on biomarkers of estrogenic exposure, however estrone concentrations of 85 ng/L and greater corresponded with significantly increased plasma VTG and reduced body condition factor compared to control. Low dissolved oxygen significantly elevated plasma VTG concentrations of P. promelas exposed to 15 ng/L (nominal) and 51 ng/L (measured) aqueous E1, however this effect diminished to below the threshold of statistical significance (p<0.05) upon exposure to a “high” E1 concentration (100 ng/L [nominal] and 390 ng/L [measured]). Significant reductions in hematocrit and gonadosomatic index compared to control were also noted at high estrone concentrations. These data indicate that environmental conditions can modulate the effects of estrogenic exposure in male P. promelas. We anticipate that accounting for a variety of environmental conditions might be a starting point for laboratory exposures designed to assess the environmental impact of estrogenic CECs.

Technical Abstract: Laboratory exposure data indicate that estrogens and estrogen mimics can cause endocrine disruption in male fathead minnows (Pimephales promelas). In the wild, conditions are not static as is often the case in the laboratory. Changes in water quality parameters, such as salinity influx due to road salt intrusion and aquatic hypoxia due to cultural eutrophication, can trigger physiological and anatomical changes in fish that have the potential to alter the uptake and observed effects of estrogenic chemicals. To explore the role of environmental variables on the expression of biomarkers of estrogenic exposure, adult male P. promelas were exposed to estrone (E1) under various chloride and dissolved oxygen conditions in the laboratory for 21 days in a flow-through system. Plasma vitellogenin (VTG), morphological characteristics, hematological parameters, and histopathology were assessed to determine the severity of estrogenic effect. Salinity at 50 PPM added NaCl had no significant effect on biomarkers of estrogenic exposure, however estrone concentrations of 85 ng/L and greater corresponded with significantly increased plasma VTG and reduced body condition factor compared to control. Low dissolved oxygen significantly elevated plasma VTG concentrations of P. promelas exposed to 15 ng/L (nominal) and 51 ng/L (measured) aqueous E1, however this effect diminished to below the threshold of statistical significance (p<0.05) upon exposure to a “high” E1 concentration (100 ng/L [nominal] and 390 ng/L [measured]). Significant reductions in hematocrit and gonadosomatic index compared to control were also noted at high estrone concentrations. These data indicate that environmental conditions can modulate the effects of estrogenic exposure in male P. promelas. We anticipate that accounting for a variety of environmental conditions might be a starting point for laboratory exposures designed to assess the environmental impact of estrogenic CECs.