Plastics chemical retards growth, function of adult reproduc...( CHAMPAIGN Ill. Bisphenol A a chemic...)

CHAMPAIGN, Ill. Bisphenol A, a chemical widely used in plastics and known to cause reproductive problems in the offspring of pregnant mice exposed to it, also has been found to retard the growth of follicles of adult mice and hinder their production of steroid hormones, researchers report.

Their study is the first to show that chronic exposure to low doses of BPA can impair the growth and function of adult reproductive cells. The researchers will describe their findings this month at the annual meeting of the Society for the Study of Reproduction.

A healthy, mature follicle, called an antral follicle, includes a single egg cell surrounded by layers of cells and fluid which support the egg and produce steroid hormones, said University of Illinois veterinary biosciences professor Jodi Flaws, who led the study with graduate student Jackye Peretz.

"These are the only follicles that are capable of ovulating and so if they don't grow properly they're not going to ovulate and there could be fertility issues," Flaws said. "These follicles also make sex steroid hormones, and so if they don't grow properly you're not going to get proper amounts of these hormones." Such hormones are essential for reproduction, she said, "but they're also required for healthy bones, a healthy heart and a healthy mood."

BPA is widely used in plastics and is a common component of food containers and baby bottles.

The chemical structure of BPA is similar to that of estradiol, a key steroid hormone, and it can bind to estrogen receptors on the surface of some cells. It is not known whether BPA blocks, or mimics or enhances estrogen's activity on these cells, Flaws said.

Human studies have found BPA in many tissues and fluids, including urine, blood, breast milk, the amniotic fluid of pregnant women and the antral fluid of mature follicles. A national survey conducted by the federal Centers for Disease Control and Prevention in 2003-2004 fou
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