For years, scientists have been concerned about chemicals in the environment that mimic the estrogens found in the body. In study after study, researchers have found links between these "xenoestrogens" and such problems as decreased sperm viability, ovarian dysfunction, neurodevelopmental deficits and obesity. But experimental limitations have prevented them from exploring one of the most serious questions posed by exposure to xenoestrogens: what happens when as in the real world an individual is exposed to multiple estrogen-mimicking chemicals at the same time?
Now University of Texas Medical Branch at Galveston researchers have used new techniques to study exposure to low doses of multiple xenoestrogens. And they've come to some disturbing conclusions.
Using cell cultures to test mixtures of three compounds known to affect estrogen signaling, bisphenol A (found in plastic bottles and the linings), bisphenol S (a supposedly safer replacement for bisphenol A recently found to have similar effects) and nonylphenol (a common component of industrial detergents and surfactants) the scientists determined that combinations of endocrine disruptors could have a dramatically greater effect than any one of them alone.
"We wanted to see how these persistent, ubiquitous contaminants affect estrogenic signaling when they're mixed together as they are in nature, so we set up a cell-culture system that allowed us to test their influence on signaling by estradiol, the estrogen found in adult, cycling women," said UTMB professor Cheryl Watson, senior author of a paper on the study now online in the journal Environmental Health (http://www.ehjournal.net/). "What we found is that these things gang up on estradiol and thwart its response, which is not a good thing."
Watson and her colleagues tested different mixtures of estrogen-disrupting compounds using rat pituitary cells, ce
|Contact: Jim Kelly|
University of Texas Medical Branch at Galveston