|MEETING SITE HOME SCHEDULE AUTHOR INDEX SUBJECT INDEX PROGRAM # INDEX ITINERARY SIGNUP|
TP15 Endocrine Disruption in Fish
(CRI-1117-831889) Effects of a model estrogen, 17-estradiol, on the reproductive response of the estuarine sheepshead minnow, Cyprinodon variegatus.
Cripe, G1, Hemmer, B1, Goodman, L1, Fournie, J.1, Almario, A1, Kinnunen, D2, Vennari, J2, 1 U.S. EPA, Gulf Ecology Division, Gulf Breeze, FL, USA2 Senior Environmental Employee, Gulf Ecology Division, Gulf Breeze, FL, USA
ABSTRACT- The objective of this research is to provide the Environmental Protection Agency with a transferable two-generation toxicity test guideline using the sheepshead minnow, Cyprinodon variegatus. The short life-cycle of this estuarine fish provides the opportunity to efficiently obtain chemical effects information on vertebrate endocrine systems over multiple generations. Longer-duration exposures spanning critical life stages over multiple generations can identify and characterize possible latent or cumulative adverse effects of endocrine disrupting chemicals occurring throughout the organism's life history. Development of a two-generation test guideline provides the information necessary to assess the reliability of shorter-term, one-generation reproductive assays to detect adverse multi-generational effects. In addition, comparisons are being made with other testing approaches, endpoints and exposure periods for their potential to singularly or collectively indicate reproductive impairment. In this study, techniques employed in established one-generational exposure guidelines to measure reproductive responses were refined and evaluated using an exposure to 17-estradiol. Embryo production from four replicate spawning groups in each of five treatments was monitored daily for 14 days prior to, and during 20 days of continuous exposure. The highest concentration, 0.5g 17-estradiol/L, significantly ( ≤ 0.05) reduced production of fertile eggs by 43 percent. Reproductive impairment will be compared to specific indicators of physiological condition, including vitellogenin induction, plasma steroid levels, and histopathological changes in gonads, liver and thyroid. This research supports international harmonization of endocrine disruptor test methods currently under development by both EPA and OECD.
Key words: sheepshead minnows, Cyprinodon variegatus, estradiol, reproduction
Internet Services provided by|
Allen Press, Inc. | 810 E. 10th St. | Lawrence, Kansas 66044 USA
e-mail firstname.lastname@example.org | Web www.allenpress.com
All content is Copyright © 2005 SETAC