EARLY LIFE STRESS AND PHARMACEUTICAL POLLUTANTS: DEVELOPMENTAL TOXICITY OF EMERGING AQUATIC CONTAMINANTS IN A MODEL TERRESTRIAL SPECIES

ECU Author/Contributor (non-ECU co-authors, if there are any, appear on document)

Jacqueline Ruth Meadows (Creator)

Institution

East Carolina University (ECU )

Web Site: http://www.ecu.edu/lib/

Abstract: Trace amounts of pharmaceutical and personal care products are plaguing water sources around the globe , and with no current regulations , these emerging contaminants pose a threat to environmental and human health. While there are dozens of studies describing the toxicity of pharmaceutical pollutants in aquatic organisms , virtually no studies exist pertaining to the potential impacts of environmentally relevant concentrations of these biologically active compounds on terrestrial beings. Further , even less is known about the potential hazards to susceptible populations and the long-lasting effects of chronic exposure. In this dissertation , we investigated the effects of developmental exposure to three abundantly detected pharmaceuticals , fluoxetine , fenofibrate , and norethisterone , in an in ovo chicken model , a well-accepted model of developmental ecotoxicity. Following developmental exposure , general biomarkers of toxicity were evaluated in addition to biomarkers associated specifically with the stress axis. We hypothesized that the developmental stress axis , a highly conserved system among vertebrate species , would serve as a sensitive axis that can be altered by pharmaceutical pollutant exposure. Indeed , in one day old chicken hatchlings , we detected alterations within the stress axis , particularly in DNA methylation alterations. In subsequent studies , we observed persistent molecular changes within the stress axis , including lowered basal corticosterone levels , reduced glucocorticoid receptor content , and insufficient immune responses in developmentally exposed chickens raised to two weeks old. Additionally , we suggest key components of an adverse outcome pathway that could help describe the toxicity of pharmaceutical pollutants in a non-aquatic species. Together , these experiments demonstrate , for the first time , the toxicity of environmental concentrations of pharmaceutical pollutants in a sentinel terrestrial species.

Additional Information

Publication

Dissertation

Language: English

Date: 2019

Keywords

Pharmaceutical Pollutants, Fluoxetine, Early Life Stress, HPA Axis

Subjects

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