Xenoestrogens Adversely Distort Natural Hormone Activity

Mounting evidence links "xenoestrogens" In mixtures expected to be found in contaminated environments, xenoestrogens can have dramatic disrupting effects on hormonal mechanisms of cell regulation and their downstream functional responses, altering cellular responses to physiologic estrogens. chemicals in the environment that mimic the estrogens found in the human body – and health problems including  decreased sperm viability, ovarian dysfunction, neurodevelopmental deficits and obesity.  University of Texas Medical Branch (Texas, USA) researchers utlize new techniques to study exposure to low doses of multiple xenoestrogens – to ascertain what happens when — as in the real world — an individual is exposed to multiple estrogen-mimicking chemicals at the same time.  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) — Cheryl Watson and colleagues determined that combinations of endocrine disruptors could have a dramatically greater effect than any one of them alone.  The team 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.  The study investigators warn that: “In mixtures expected to be found in contaminated environments, xenoestrogens can have dramatic disrupting effects on hormonal mechanisms of cell regulation and their downstream functional responses, altering cellular responses to physiologic estrogens.”