Neuroendocrine Disruption by 17α-ethinylestradiol and Bisphenol-a in Zebrafish


Taelah Wooten

Document Type


Degree Name

Master of Science (MS)


Biological Sciences

Date of Award

Summer 2017


Aquatic organisms are highly susceptible to endocrine disruption due to increased accumulation of estrogenic endocrine disrupting chemicals (EDCs) in surface waters. The consequence of EDC exposure has not been well characterized in the adult male reproductive neuroendocrine system, although there is considerable circumstantial evidence for neuroendocrine disruption based on limited information available in the literature. This study was designed to evaluate the effects of environmental contaminants 17α-ethinylestradiol (EE2) and bisphenol-A (BPA) on adult male zebrafish reproduction. It was hypothesized that EE2 and BPA will act as estrogen mimics to inhibit the male hypothalamus-pituitary-gonadal (HPG) axis. In the first experiment, adult male zebrafish in three treatment groups were injected with 0.1, 1, or 10 nmol/kg EE2, once a week for three weeks. The control received sham injections. At the end of the three weeks, whole brain tissue samples were collected and analyzed for changes in Kisspeptin (Kiss) using a commercially purchased Kiss enzyme linked immunoassay kit. Gonadal samples were collected for evaluation of any histopathological changes in the testes and water samples, after immersing individual fish in 100 ml water for one hour, were collected to evaluate sex steroid production. A similar experiment was performed using 0.1,1, and 10 μmol/kg BPA injections and the same neuroendocrine and reproductive parameters were evaluated after the 3-week exposure period.


Izhar Khan

Subject Categories

Biochemistry, Biophysics, and Structural Biology | Biology | Life Sciences