Navigation Links
Combinations of estrogen-mimicking chemicals found to strongly distort hormone action

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 ( "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, cells that are master regulators of the animals' endocrine systems. Their experiments measured the responses of key signaling pathways that lead to cell proliferation, the secretion of the pituitary hormone prolactin and the activation of proteins involved in apoptosis (programmed cell death), comparing the effects of estradiol alone with those of estradiol and mixtures of bisphenol A, bisphenol S and nonylphenol.

"These compounds work at very low concentrations at the parts per trillion or parts per quadrillion level and when you mix them together they affect estrogenic signaling differently and more dramatically than they do individually," Watson said. "We need to pay attention to this, because estrogens influence so many things in both males and females reproduction, the immune system, metabolism, bone growth, all sorts of important biological functions."

Studies have detected measurable levels of bisphenol A and bisphenol S in the urine of more than 90 percent of Americans. According to Watson, modern humans are exposed to dozens of xenoestrogens more or less continually.

"These things are all over the environment, and we need to know what they do so we can start figuring out what we need to change," Watson said. "They're probably disrupting and confusing hormones in people, and it's important to find a way to prevent that as soon as we can. We need to test these compounds for their hormone-disrupting activities before they are put into products, so we can redesign for safety very early in the process."

Contact: Jim Kelly
University of Texas Medical Branch at Galveston

Related biology news :

1. Cats are able to navigate complex combinations of wet and dry foods to achieve a consistent intake of protein, fat and carbohydrate
2. Yale Study links common chemicals to osteoarthritis
3. Numerical study suggests subsea injection of chemicals didnt prevent oil from rising to sea surface
4. Chemicals today, drugs tomorrow: U-Ms new Center for Drug Discovery
5. Hearing the telltale sounds of dangerous chemicals
6. Hormone-mimicking chemicals cause inter-species mating
7. Production of chemicals without petroleum
8. Effect of chronic exposure to chemicals used as weapons, pesticides under study
9. Brain & Behavior Research Foundation announces spring 2013 conference & free webinars
10. Brain & Behavior Research Foundation awards nearly $4 million in new NARSAD grants
11. Origins of human teamwork found in chimpanzees
Post Your Comments:
(Date:10/29/2015)... 29, 2015  The J. Craig Venter Institute (JCVI) ... Synthesis and Biosecurity: Lessons Learned and Options for the ... and Human Services guidance for synthetic biology providers has ... --> --> Synthetic biology ... potential to pose unique biosecurity threats. It now is ...
(Date:10/29/2015)... 2015 Today, LifeBEAM , a ... 2XU, a global leader in technical performance sports ... with advanced bio-sensing technology. The hat will allow ... key biometrics to improve overall training performance. As ... will bring together the most advanced technology, extensive ...
(Date:10/26/2015)... and LAS VEGAS , Oct. ... Labs , an innovator in modern authentication and a ... announced the launch of its latest version of the ... enabling organizations to use standards-based authentication that supports existing ... S3 Authentication Suite is ideal for organizations deploying customer-facing ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... -- Halozyme Therapeutics, Inc. (NASDAQ: HALO ) will be presenting ... on Wednesday, December 2 at 9:30 a.m. ET/6:30 a.m. ... will provide a corporate overview. th Annual Oppenheimer ... p.m. ET/10:00 a.m. PT . Jim Mazzola , vice ... overview. --> th Annual Oppenheimer Healthcare Conference in ...
(Date:11/24/2015)... ... November 24, 2015 , ... Copper is an essential micronutrient ... to proteins, copper is also toxic to cells. With a $1.3 million award ... will conduct a systematic study of copper in the bacteria Pseudomonas aeruginosa (P. ...
(Date:11/24/2015)... QUEBEC CITY , Nov. 24, 2015 /PRNewswire/ - ... the request of IIROC on behalf of the Toronto ... this news release there are no corporate developments that ... price. --> --> ... --> . --> Aeterna Zentaris ...
(Date:11/24/2015)... 2015 --> ... "Oligonucleotide Synthesis Market by Product & Services (Primer, Probe, ... DNA, RNAi), End-User (Research, Pharmaceutical & Biotech, Diagnostic Labs) ... market is expected to reach USD 1,918.6 Million by ... CAGR of 10.1% during the forecast period. ...
Breaking Biology Technology: