M4 PM Endocrine Disruption in Fish (Part 2)
Monday, 14 November 2005: 1:50 PM - 5:30 PM in Ballroom 4

(MAY-1117-837209) Analysis of zebrafish embryos esposed to natural and synthetic estrogen mixtures.

Mayer, G¹, Notch, E¹, ¹ University of Maine, Orono, ME, USA

ABSTRACT- Recently, much attention has been given to endocrine active compounds in the environment. One class of xenoestrogens includes the synthetic estrogens commonly found in pharmaceuticals such as birth control agents and hormone replacement therapies. Synthetic estrogens such as these mimic natural estrogens well at the receptor level, but are more resistant to degradation by natural processes (1.2 d for E2 vs. 17 d for EE2). Because of its greater stability and higher potency in vivo, EE2 may be of disproportional toxicological importance despite being found at much lower concentrations than natural steroids such as E2 and E1. In addition, combinations of estrogenic species have been shown to synergistically upregulate vitellogenin protein levels as assayed by RIA. We investigate the use of a bioassay for estrogenic potential of synthetic estrogens that utilizes the activation of the Xenopus vitellogenin promoter and the subsequent expression of luciferase as a surrogate for whole animal estrogen response. These data will be correlated to actual vitellogenin transcriptional responses in finfish embryos after exposure to E1, E2, EE2, and combinations thereof.

Key words: ethinylestradiol, estrone, vitellogenin