In an article published on January 22, 2015 on the news provider Environmental Health News journalist Brian Bienkowski reports on a new study suggesting that low, brief early-life exposures to bisphenol A (BPA, CAS 80-05-7), or other substances with estrogenic activity, can alter the stem cells responsible for producing sperm later in life. Such exposures could therefore contribute to declining sperm counts in men observed worldwide over the past few decades. In the new study, published in the peer-reviewed journal PLoS Genetics, Vrooman and colleagues from Washington State University, U.S. orally exposed one group of newborn male mice to BPA (20 or 500 ng/g body weight (bw)/day) and another group to ethinyl estradiol (EE, 0.25 ng/g bw/day), a synthetic estrogen used in birth control pills and hormone replacement therapy. These exposures, comparable to exposures humans experience, have led to permanent alterations to the stem cells responsible for sperm production, the authors say. The researchers further transplanted the stem cells from exposed male mice into healthy unexposed animals and verified the adverse impacts on sperm development.
Brian Bienkowski (January 22, 2015). “BPA exposure linked to changes in stem cells, lower sperm production.” Environmental Health News
Vrooman, L.A. et al. (2015). “Estrogenic exposure alters the spermatogonial stem cells in the developing testis, permanently reducing crossover levels in the adult.“ PLoS Genetics (open access, published online January 23, 2015).