Meeting Abstract

P3.71  Sunday, Jan. 6  Thyroid Endocrine Disruption in Coastal California Fish LEE, E*; REYES, J; FORSGREN, K; WAGGONER, C.M.; KELLEY, K.M.; California State University, Long Beach; Pacific Coast Environmental Conservancy, California; California State University, Fullerton; Institute for Integrative Research on Materials, Environment and Society, California, Long Beach; California State University, Long Beach bob71488@gmail.com

In urban coastal southern California and in San Francisco Bay, several fish species have been found to exhibit significant location-related alterations in plasma concentrations of thyroxine (T4) and triidothyronine (T3), suggestive of endocrine disruption in the thyroid axis. Reduced T4 is commonly seen when fish are sampled from contaminated locations, and our studies indicate that this is significantly correlated with fish exposures to certain chemical classes including polychlorinated biphenyls (PCBs; mostly non-coplanar, lower-chlorinated congeners). Alterations in T3 levels and in T3/T4 ratio suggest that 5’-monodeiodinase activity may play a role in the thyroid hormone disturbances; assays of hepatic deiodinase activity support this as one underlying mechanism. In addition, it was found that the thyroid gland itself may also be impacted, since treatment of impacted fish with pituitary thyroid-stimulating hormone (TSH) failed to normally activate T4 production. Additional studies are characterizing thyroid tissue histophysiology and protein expression, in addition to screening for changes in hepatic proteins, as part of a project aimed at characterizing the thyroid disrupted condition in these wild fish. [support by NOAA-USC Sea Grant Program and Pacific Coast Environmental Conservancy]