You are here:
ISSUES IN ENDOCRINE DISRUPTION: COMPARING CRITICAL PERIODS OF HORMONE SENSITIVITY
Citation:
Foran, C M. AND W H. Benson. ISSUES IN ENDOCRINE DISRUPTION: COMPARING CRITICAL PERIODS OF HORMONE SENSITIVITY. Presented at Chesapeake Potomac Regional Chapter of SETAC (Spring), Shepardstown, WV, 4/22/04.
Description:
Japanese medaka (Oryzias latipes) have been developed as a model species to compare the effects of endocrine active chemicals at critical life-stage periods of hormonal sensitivity, specifically as reproductively active adults, during the developmental period of differentiation, and parental or in ovo exposure. Assessment of reproductive output of exposed adults can be correlated to changes in physiological function along the reproductive axis, including circulating steroid hormone concentrations, ex vivo steroidogenesis from the gonads, pituitary responsiveness to gonadotropin releasing hormone, hepatic estrogen receptor content, and hepatic vitellogenin. Many biomarkers of exposure have been developed for chemicals that have the potential to impact reproductive function. These methods are effective for detecting exposure to xenobiotics, but there is little information indicating that they can be used to predict exposure related reproductive impairment. The exposure literature for teleosts, and for mammals, has demonstrated that the relationship between exposure and effects is complicated by the timing of exposure and the mechanism of action of the chemical exposures. In medaka, early developmental exposure and re-exposure as an adult resulted in a different response than either single treatment alone.