Toxic Substances Hydrology Program
Biological Activity of Steroid Hormones in U.S. Streams
Testing of U.S. streams has detected glucocorticoid and androgen biological activity. In a collaborative study between the National Cancer Institute (NCI), Laboratory of Receptor Biology and Gene Expression, the U.S. Geological Survey (USGS), and others, scientists studied the potential for the biological activity in streams of glucocorticoids and androgens hormones—both potential endocrine-disrupting chemicals. Scientists tested water samples using a new cell-based bioassay that tested for molecular responses triggered by the presence of glucocorticoids and androgens in water. They found glucocorticoid and androgen activity in 27 and 35 percent of the water samples, respectively, potentially indicating the widespread occurrence of these hormones in streams.
Glucocorticoids—steroid hormones commonly referred to as "stress hormones"—are known for their potential to decrease immune responses. Glucocorticoid-based pharmaceuticals (hydrocortisone and prednisone, for example) are widely prescribed to relieve inflammation. Androgens are anabolic steroids that affect the development and maintenance of male characteristics, as well as other physiological functions. Depending on the timing of exposure, glucocorticoids and androgens can affect the endocrine systems of living organisms, but unlike estrogenic chemicals, not much is known about their occurrence in the environment.
USGS scientists provided extracts for testing from more than 100 water samples from streams and rivers located in 14 States. The testing method the NCI researchers developed allowed them to detect the activation of cell receptors or genes that respond specifically to glucocorticoids or androgens. Activation of fluorescently tagged cell receptors led to visual evidence of the presence of glucocorticoids or androgens in the samples of stream water. Other molecular methods were used to confirm that specific genes were turned on.
Considering that both glucocorticoids and androgens influence body development and metabolism, and have the potential to influence normal reproductive, endocrine, and immune system function, their presence in the environment has potential implications for wildlife and human health.
This study was funded by:
Stavreva, D.A., George, A.A., Klausmeyer, P., Varticovski, L., Sack, D., Voss, T.C., Schiltz, R.L., Blazer, V.S., Iwanowicz, L.R., and Hager, G.L., 2012, Prevalent glucocorticoid and androgen activity in US water sources: Science Reports, v. 2 (Supplementary information).
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