You are here:
Development of a Computational Model for Female Fathead Minnows exposed to Two Endocrine Disrupting Chemicals
Citation:
LI, Z., K. J. KROLL, N. G. GARCIA-REYERO, DAN VILLENEUVE, M. SEPULVEDA, E. F. ORLANDO, G. T. ANKLEY, N. DENSLOW, AND K. WATANABE. Development of a Computational Model for Female Fathead Minnows exposed to Two Endocrine Disrupting Chemicals. Presented at PNW SETAC Meeting, Port townsend, WA, April 16 - 18, 2009.
Impact/Purpose:
Endocrine disrupting chemicals (e.g., estrogens and androgens) are known to affect reproductive functions in fish
Description:
Endocrine disrupting chemicals (e.g., estrogens and androgens) are known to affect reproductive functions in fish. A synthetic estrogen used in birth control pills, 17á-ethynylestradiol (EE2), is discharged from wastewater treatment plants into water bodies throughout the United States. 17â-trenbolone (TB) is a relatively stable metabolic product of trenbolone acetate, a synthetic androgen used as a growth promoter for cattle. TB enters the environment mainly through runoff from cattle feedlots. In this study, we developed a physiologically based computational model of female fathead minnows (FHM, Pimephales promelas) to simulate how EE2 or TB affects reproductive endpoints, such as concentrations of steroid hormones (17-estradiol (E2), and testosterone (T)) and vitellogenin (Vtg, a precursor to egg yolk proteins). The model contains six tissue compartments, and mass balances are used to formulate a set of differential equations describing E2, T, EE2, TB, and Vtg kinetics in each compartment. The model was calibrated with data from 75 unexposed FHMs, 59 FHMs exposed to 0.005, 0.05, 0.5, 5, and 50 ug TB/L for 21 days, and 61 FHMs exposed to 10 and 100 ng EE2/L for 8 days followed by 8-day depuration. Once calibrated, the model will be evaluated with independent experimental data from 23 FHMs exposed to 0.005, 0.05, 0.5 ug TB/L for 2 days, 30 FHMs exposed to 0.005, 0.05, 0.5 ug TB/L for 14 and 28 days, and 4 FHMs exposed to 1.5 ng EE2/L for 21 days. The model can be used to estimate the effects of EE2 or TB exposure in female FHMs, and may also be used to study effects upon the biochemical processes related to steroidogenesis.