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EFFECTS OF ENVIRONMENTAL CHEMICALS ON FETAL TESTES TESTOSTERONE PRODUCTION
Citation:
Lambright, C R., V S. Wilson, J. R. Furr, C J. Wolf, N C. Noriega, AND L E. Gray Jr. EFFECTS OF ENVIRONMENTAL CHEMICALS ON FETAL TESTES TESTOSTERONE PRODUCTION. Presented at Triangle Consortium for Reproductive Biology, (EPA) RTP, NC, February 1, 2003.
Description:
Effects of Environmental Chemicals on Fetal Testes Testosterone Production
Lambright, CS , Wilson, VS , Furr, J, Wolf, CJ, Noriega, N, Gray, LE, Jr.
US EPA, ORD/NHEERL/RTD, RTP, NC
Exposure of pregnant rodents to certain environmental chemicals during critical periods of fetal development can have profound effects on the reproductive system. In this study, we examined the effects of gestational exposure to eight different environmental chemicals on fetal testes testosterone production. These chemicals include fungicides (Procymidon (PD), Vinclozolin (V), Prochloraz (PZ)), phthalates (DEHP, DBP, BBP) and herbicides (Linuron (L), Neburon (N)). Doses of 200, 200, 250, 1000,1000,1000, 100, 100 mg/kg/day respectively were chosen such that 100% of the fetuses would be affected. Previous studies with DEHP have shown a reduction in fetal T production. We anticipate that both DBP and BBP will act by the same mechanism with BBP being approximately as potent as DEHP. L has been shown to reduce fetal T production in previous studies. N, also a urea based herbicide, is being evaluated as its effects are largely unknown but anticipated to be similar to L. V and PD are AR antagonists and are expected to have no effect fetal T production. PZ has been shown to be an aromatase inhibitor but the effect on fetal T production is unknown. Dams were dosed daily from GD 14-18, sacrificed on GD 18, fetal testes removed and incubated in M199 media supplemented with 10% DCC serum for 3 hours. Media was removed and saved for assays.
Of the chemicals, L, N, DEHP, DBP, BBP, PZ. all caused a significant reduction in fetal testes testosterone production. As anticipated, V and PD treatment did not reduce testosterone production. We also examined the progesterone levels in the media and found that PZ exposure resulted in a 20 fold increase over control whereas none of the other chemicals had an affect.
These studies provide excellent background from which we can use to further investigate the mechanisms behind which this diverse group of chemicals affect fetal testes testosterone production following gestational exposure.
This is an abstract of a proposed presentation and does not necessarily reflect USEPA policy.