Bisphenol A exposure in pregnant mice permanently changes DNA of offspringJune 11, 2009Exposure during pregnancy to the chemical bisphenol A, or BPA, found in many common plastic household items, is known to cause a fertility defect in the mother's offspring in animal studies, and now researchers have found how the defect occurs. The results of the new study will be presented Saturday at The Endocrine Society's 91st Annual Meeting in Washington, D.C. The study, funded partly by the National Institutes of Health, joins a growing body of animal research showing the toxic health effects of BPA, including reproductive and developmental problems. Last August the U.S. Food and Drug Administration found BPA to be safe as currently used but later said more research on its safety is needed. BPA is used to make hard polycarbonate plastic, such as for baby bottles, refillable water bottles and food containers, as well as to make the linings of metal food cans. BPA has estrogen-like properties and in pregnant animals has been linked to female infertility. "The big mystery is how does exposure to this estrogen-like substance during a brief period in pregnancy lead to a change in uterine function," said study co-author Hugh Taylor, MD, professor and chief of the reproductive endocrinology section at Yale University School of Medicine. To find the answer to that question, Taylor and his co-workers at Yale injected pregnant mice with a low dose of BPA on pregnancy days 9 to 16. After the mice gave birth, the scientists analyzed the uterus of female offspring and extracted DNA. They found that BPA exposure during pregnancy had a lasting effect on one of the genes that is responsible for uterine development and subsequent fertility in both mice and humans (HOXA10). Furthermore, these changes in the offspring's uterine DNA resulted in a permanent increase in estrogen sensitivity. The authors believe that this process causes the overexpression of the HOXA10 gene in adult mice that they found in previous studies. The permanent DNA changes in the BPA-exposed offspring were not apparent in the offspring of mice that did not receive BPA injection (the controls). This finding demonstrates that the fetus is sensitive to BPA in mice and likely also in humans, Taylor said. "We don't know what a safe level of BPA is, so pregnant women should avoid BPA exposure," Taylor said. "There is nothing to lose by avoiding items made with BPA-and maybe a lot to gain." The Endocrine Society |
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| Related Bisphenol A Current Events and Bisphenol A News Articles Plastics chemical retards growth, function of adult reproductive cells 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. BPA, chemical used to make plastics, found to leach from polycarbonate drinking bottles into humans A new study from Harvard School of Public Health (HSPH) researchers found that participants who drank for a week from polycarbonate bottles, the popular, hard-plastic drinking bottles and baby bottles, showed a two-thirds increase in their urine of the chemical bisphenol A (BPA). Inexpensive plastic used in CDs could improve aircraft, computer electronics If one University of Houston professor has his way, the inexpensive plastic now used to manufacture CDs and DVDs will one day soon be put to use in improving the integrity of electronics in aircraft, computers and iPhones. JAMA article contends earlier study overstated validity of findings on bisphenol A In a letter to be published in this week's Journal of the American Medical Association (JAMA), Dr. S. Stanley Young, Assistant Director of Bioinformatics at the National Institute of Statistical Sciences, and Ming Yu, University of British Columbia, highlight the statistical limitations of a study claiming that bisphenol A is associated with cardiovascular diagnoses, diabetes and abnormal blood level liver enzyme levels. Rochester study raises new questions about controversial plastics chemical A University of Rochester Medical Center study challenges common assumptions about the chemical bisphenol A (BPA), by showing that in some people, surprisingly high levels remain in the body even after fasting for as long as 24 hours. The finding suggests that BPA exposure may come from non-food sources, or that BPA is not rapidly metabolized, or both. Persistent pollutant may promote obesity Tributyltin, a ubiquitous pollutant that has a potent effect on gene activity, could be promoting obesity, according to an article in the December issue of BioScience. Pollution at home lurks unrecognized, instead attributed to large-scale environmental disasters Although Americans are becoming increasingly aware of toxic chemical exposure from everyday household products like bisphenol A in some baby bottles and lead in some toys, women do not readily connect typical household products with personal chemical exposure and related adverse health effects, according to research from the December issue of the Journal of Health and Social Behavior. Household Exposure to Toxic Chemicals Lurks Unrecognized, Researchers Find Although Americans are becoming increasingly aware of toxic chemical exposure from everyday household products like bisphenol A in some baby bottles and lead in some toys, women do not readily connect typical household products with personal chemical exposure and related adverse health effects. Research shows link between bisphenol A and disease in adults A research team from the Peninsula Medical School, the University of Exeter, the University of Plymouth and the University of Iowa, have found evidence linking Bisphenol A (BPA) to diabetes and heart disease in adults. Bisphenol A linked to chemotherapy resistance Exposure to bisphenol A (BPA) may reduce the effectiveness of chemotherapy treatments, say University of Cincinnati (UC) scientists. More Bisphenol A Current Events and Bisphenol A News Articles |
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