Reproductive Toxicology Division
Reproductive Toxicology Division
Research Teams
Abnormal Reproductive Development Team (ARD)
The Abnormal Reproductive Development Team’s research, led by Dr. L. Earl Gray, integrates results from in vivo studies on the impact of chemicals, particularly endocrine disruptors, on reproductive development, with molecular and cell-based approaches to define modes/mechanisms of action. Also applies in vitro receptor assays to monitor EDCs in the environment. More
- Recent Accomplishments: Developed a recombinant chimpanzee androgen receptor and incorporated it into a cell-based assay to screen for environmental antiandrogens.
- Ongoing Studies: Evaluating mixtures of antiandrogens with common or differing modes of action.
- New Projects: Do fetal exposures impact reproductive behavior later in life, or produce adverse effects through epigenetic mechanisms?
Drinking Water Team (DW)
The Drinking Water Team’s research, led by Dr. Sid Hunter has evolved from the examination of individual chemicals to the potential impact of defined and real-world mixtures on reproduction and development. More
- Recent Accomplishments: Evaluated defined and environmental mixtures of Disinfection Byproducts (DBPs) in the “4-lab study” and an epidemiology study (The Healthy Men Study); evaluated the developmental toxicity of algal toxins.
- Ongoing Studies: Elucidating molecular mechanisms of developmental toxicity of DBPs using whole embryo culture in rodents and human placental cell culture.
- New Projects: Application of stem cell culture to predict developmental toxicity in vitro; exploring mechanisms of algal toxin toxicities.
Long Term Effects Team (LTE)
The Long Term Effects Team, led by Dr. John Rogers, examines the effects of toxicant exposure during prenatal and/or early postnatal development on risk of adverse health outcomes later in life. Undernutrition, malnutrition, or exposure to glucocorticoids during development has been shown to produce effects including elevated blood pressure, insulin resistance, obesity, and reproductive effects. These effects may in part, involve changes in the epigenome, and could potentially be heritable. The LTE team conducts experiments to determine whether developmental exposures to diverse toxicants are capable of inducing latent adverse health effects, and the role of epigenetic changes in such effects. More
- Recent accomplishments: Maternal undernutrition or prenatal exposure to dexamethasone, perfluorooctane sulfonate or atrazine in rats each caused a small decrease in birth weight. Offspring developed elevated blood pressure during the first year of life, and results of oral glucose tolerance tests indicated some derangement of the insulin response. Obesity was not observed. Prenatal exposure to perfluorooctanoic acid in mice resulted in effects on mammary gland development, and increased body weight later in life.
- Ongoing studies: Evaluating blood pressure, fatty acid metabolism, and lactational competence in adult offspring exposed to toxicants in utero.
- New projects: Examining developmental toxicants with differing modes of action for long-term effects; developing improved methods to evaluate kidney development using confocal microscopy.
Neuroendocrine Function Team (NEF)
The Neuroendocrine Function Team, led by Dr. Ralph Cooper, addresses the issue of common modes of action through which chemicals may impact the neuroendocrine control of reproduction. More
- Recent Accomplishments: Elucidated modes of action of atrazine that contributed to the recent risk assessment.
- Ongoing Studies: Examining novel mechanisms for the chlorotriazine family of compounds and their metabolites, including the potential role of altered aromatase activity.
- New Projects: Applying cell-based assays and molecular markers to assess neuroendocrine function and sexual differentiation of the brain.
Perfluoroalkyl Acids Team (PFAA)
The Perfluoroalkyl Acids Team, led by Dr. Christopher Lau, examines the reproductive and cancer risks of perfluorinated compounds such as PFOS, PFOA and related chemicals (PFAAs). More
- Recent Accomplishments: Using knock-out mouse models and genomics, recently clarified the importance of PPAR activation in the developmental toxicity of PFOA, an issue identified for study by the Science Advisory Board on PFAAs. Documented the mouse as an appropriate model for humans exposed to PFOS and PFOA.
- Ongoing Studies: Examining pharmacokinetics of PFAAs with respect to pregnancy, lactation and delivery to brain in newborns.
- New Projects: Exploring effects and mechanisms of toxicity for other PFAAs (in addition to PFOS/PFOA) that are relevant to human health risk assessment.
Support to EPA’s Endocrine Disruptor Screening Program (EDSP)
In response to concerns that environmental chemicals may adversely affect human health by altering endocrine function, Congress mandated that the EPA develop an endocrine disruptor screening program (EDSP). To address the mandates, this effort has the task of developing a battery of novel and updated, in vivo and in vitro, screening and testing assays which are undergoing validation. More