PROPPER, CR*; Northern Arizona University: Non-conventional Measures of Endocrine Disruption: From Orphan Nuclear Receptors to Pheromones

Over the last decade, it has become clear that human-made compounds released into the environment are disrupting the endocrine systems of animals. Research has centered largely on direct steroidogenic or antisteroidogenic effects of these compounds with a recent focus on development of rapid in vitro assays targeting the estrogen receptor. A search of the literature confirms the attention placed on the estrogen and anti-estrogen-like aspects of endocrine disruption and/or on disruption of the reproductive system. Non-steroidal components of the hypothalamic-pituitary-end gland axes have received much less attention with regards to endocrine disruption research. Furthermore, aspects of endocrine physiology, such as the ability of animals to cope with stress or communicate chemically, have also received relatively less literature attention. In our lab, we have been studying less understood outcomes of endocrine disruption using amphibian models. In the red-spotted newt, we have found that a common pesticide disrupts pheromonal communication by both affecting pheromone production and the ability to detect pheromonal signals. In bullfrogs, we have found that exposure to a common industrial pollutant rapidly induces early sexual differentiation and changes production of steroidogenic factor 1 (SF-1), an orphan nuclear receptor important to sexual differentiation. The advantages of these and other in vivo models is that they facilitate the measurement of multiple disruption endpoints, and they allow development of hypotheses regarding fitness risks. Last, in vivo systems that measure multiple outcomes may be used to study the mixes of compounds that are found in the environment. Such in vivo tests may detect less well-understood forms of endocrine disruption.