Bisphenol A Exposure and Cardiac Electrical Conduction in Excised Rat Hearts

Abstract

Background: Bisphenol A (BPA) is used to produce polycarbonate plastics and epoxy resins that are widely used in everyday products, such as food and beverage containers, toys, and medical devices. Human biomonitoring studies have suggested that a large proportion of the population may be exposed to BPA. Recent epidemiological studies have reported correlations between increased urinary BPA concentrations and cardiovascular disease, yet the direct effects of BPA on the heart are unknown.Objectives: The goal of our study was to measure the effect of BPA (0.1–100 μM) on cardiac impulse propagation ex vivo using excised whole hearts from adult female rats.Methods: We measured atrial and ventricular activation times during sinus and paced rhythms using epicardial electrodes and optical mapping of transmembrane potential in excised rat hearts exposed to BPA via perfusate media. Atrioventricular activation intervals and epicardial conduction velocities were computed using recorded activation times.Results: Cardiac BPA exposure resulted in prolonged PR segment and decreased epicardial conduction velocity (0.1–100 μM BPA), prolonged action potential duration (1–100 μM BPA), and delayed atrioventricular conduction (10–100 μM BPA). These effects were observed after acute exposure (≤ 15 min), underscoring the potential detrimental effects of continuous BPA exposure. The highest BPA concentration used (100 μM) resulted in prolonged QRS intervals and dropped ventricular beats, and eventually resulted in complete heart block.Conclusions: Our results show that acute BPA exposure slowed electrical conduction in excised hearts from female rats. These findings emphasize the importance of examining BPA’s effect on heart electrophysiology and determining whether chronic in vivo exposure can cause or exacerbate conduction abnormalities in patients with preexisting heart conditions and in other high-risk populations.Citation: Posnack NG, Jaimes R III, Asfour H, Swift LM, Wengrowski AM, Sarvazyan N, Kay MW. 2014. Bisphenol A exposure and cardiac electrical conduction in excised rat hearts. Environ Health Perspect 122:384–390; http://dx.doi.org/10.1289/ehp.1206157

Influence of bisfenol A on chemical coding of the nerve fibers of the cardiac apex in the domestic pig

“…Stwierdzono także, że ekspozycja na bisfenol A zwięk-sza ryzyko nadciśnienia i choroby wieńcowej (3,16,20). Pomimo stosunkowo znacznej liczby badań na temat negatywnego wpływu BPA na układ sercowo--naczyniowy (1,2,12,15,34), dokładny mechanizm tego działania nie został do końca poznany. Można przypuszczać, iż ma on związek z neurotoksyczną aktywnością bisfenolu A. Należy jednak zaznaczyć, że mimo licznych badań dotyczących wpływu BPA na komórki i włókna nerwowe (25,29), efekty jego wpływu na unerwienie serca nie zostały do tej pory opisane.…”

“…Udowodniono mianowicie, że bisfenol A po podaniu dożylnym odkłada się między innymi w sercu (44) i uszkadza znajdujące się tam mitochondria, co wpływa negatywnie na metabolizm mięśnia sercowego oraz obniża wydolność tego narządu (1,22). Inne badania wykazały, iż nawet niskie dawki bisfenolu A w diecie mogą powodować przerost mięśnia sercowego i wzrost jego wagi (24) oraz udowodniły BPA-zależne zwolnienie przewodzenia bodź-ców elektrycznych w sercu izolowanym (34). Ponadto stosunkowo dobrze poznane są stany chorobowe układu krążenia spowodowane bisfenolem A, do któ-rych należy zaliczyć: arytmię, podwyższone ciśnienie krwi, stany zapalne serca i naczyń oraz miażdżycę (2,12).…”

Effects of bisphenol A on incidence and severity of cardiac lesions in the NCTR-Sprague-Dawley rat: A CLARITY-BPA study

“…These estrogen-like effects of BPA increased arrhythmia frequencies in response to β-adrenergic stress in isolated hearts from female rats and mice, but not those of males (13). Additional in vitro studies have also demonstrated that acute exposures to high concentrations of BPA could decrease the rate and force of contractility and cardiac conduction velocity in hearts from female rats (14, 15) and to a lesser extent in the male heart (16). In vivo studies involving analysis of large numbers of male and female CD-1 or C57Bl/6n mice exposed throughout life to a wide range of BPA doses have also identified a number of sex and strain specific exposure-related effects (17–19).…”

The Adverse Cardiac Effects of Di(2-ethylhexyl)phthalate and Bisphenol A

“…Our laboratory has also examined the effects of BPA on cardiac function using excised Langendorff-perfused hearts 122 . Although we did not observe arrhythmias in our studies, BPA exposure adversely affected cardiac electrical conduction in a concentration-dependent manner.…”