BPA changes hormones that control puberty, ovulation.
Fernández, M, M Bianchi, V Lux-Lantos and C Libertun. Neonatal exposure to bisphenol A alters reproductive parameters and gonadotropin releasing hormone signaling in female rats. Environmental Health Perspectives doi:10.1289/ehp.0800267.
Hormones vital for controlling reproduction were permanently changed in female rats exposed to bisphenol A (BPA) early in life, reports a recent study from Argentina.
The study is the first to find long lasting hormonal changes when exposure occurs after birth, during critical times of development. Past studies have found similar effects when exposures occur before birth, during prenatal development.
The findings show again that BPA can affect fertility in mammals. Of the two levels tested in this study, the higher dose had lasting negative effects on the signaling hormones that control female reproductive cycles through life. This dose is slightly above what US federal agencies consider as a reference -- or a safe -- dose for humans.
Two levels of BPA were tested. Females were injected for 10 days starting from birth with either a "high" dose (10 micrograms per microliter) or a "low" dose (1 microgram per microliter).
Rats exposed to BPA showed decreased production of luteinizing hormone (LH). LH is needed for both rats and women to ovulate. The exposed rats at both doses showed earlier signs of puberty and abnormal pattern of ovulation cycle (or menstrual cycle in humans).
BPA is a common chemical found in polycarbonate plastics, epoxy resins and carbon receipts. It is one of the most highly produced chemicals in the world.
Exposure to the estrogen-like compound produces a wide range of changes -- especially related to reproductive function -- in laboratory animals. Human studies find people can be affected in similar ways.
In this study, the authors examined how BPA affects reproductive development and hormones in female adolescent and adult rats that were exposed during their first couple of weeks of life. The exposure time frame corresponds to infancy through pre-puberty in humans.