Females may be at a much greater risk than males from exposure to bisphenol A (BPA), a new study proposes from University of Cincinnati scientists.
“The overall aim of the study was to determine whether there were effects of BPA on cardiac function,” says team leader Scott Belcher, Ph.D., professor of pharmacology and biophysics. “We chose a very specific and broad range of BPA exposures that span levels below those considered safe in humans up through a high dose that nears the no observed adverse effect level, an approach aimed at making the findings useful for assessing public health risk.”
Investigators found the female mice exposed to BPA and isoproterenol, a drug that ultimately leads to cardiac hypertrophy by simulating some of the effects of a heart attack, led to elevated cardiac muscle damage and collagen deposition, indicative of tissue scarring. Conversely, under the same conditions male mice only exhibited fibrosis and not hypertrophy or ischemic damage.
“We used an isoproterenol model that in some ways mimics damage that can occur during a heart attack. For female mice exposed to BPA there was a severe increase in the sensitivity to cardiotoxic damage. This effect was especially striking because females are typically protected,” notes Dr. Belcher.
BPA, an environmental contaminant heavily used in the production of polycarbonate plastics and epoxy resigns, mediates its effects through the estrogen receptor and has been linked to increased risk for obesity, diabetes, and cardiovascular disease.
The results of this study (“Bisphenol A Alters Autonomic Tone and Extracellular Matrix Structure and Induces Sex-Specific Effects on Cardiovascular Function in Male and Female CD-1 Mice”) were published in the online issue of Endocrinology.
Mice were exposed to varying doses of BPA contained within their feed. Doses ranged from just below the no observed adverse effect levels to concentrations below what is considered safe (4 – 5,000 micrograms). Since it is believed that humans are continuously exposed to BPA throughout their life, Dr. Belcher and his team felt it important to expose their mice from conception to adulthood in order to closely mimic human conditions.
The research team acknowledges that their study uses animal models and cautions drawing wide parallels to humans, but maintains that their data suggests a real cellular phenomenon that warrants in-depth analysis for humans.
“The reality is everything from what we have seen from this study and a number of previous studies suggest that BPA likely worsens heart health in women, who have unique risks compared to men,” Dr. Belcher concludes.