Ventricular Fibrosis from Prolonged Bisphenol A Exposure

Abstract

Bisphenol A is an environmental toxin released from plastics and has been shown to directly affect the coronary arteries and smooth muscle resulting in cardiac dysfunction leading to an increase in arrhythmias and coronary artery disease. Positive correlations between chemical dose exposure and increases in blood pressure have also been observed which could potentially lead to sustained hypertension, a primary cause of fibrosis. Whether such fibrosis also occurs in the myocardium remains to be determined. For the first time, the histological effects of chronic BPA exposure were investigated on the ventricular myocardium and on the media of a peripheral artery, in a rat model. Methods: A total of 24 rats were divided into three groups: A) untreated control; B) vehicle control; C) BPA group. The BPA was dissolved in corn oil and group B and C received a daily IP injection of corn oil and 25 mg/kg BPA, respectively. After 3 months the animals were sacrificed, the heart was collected. Eight-mm sections were stained for collagen with Picrosirius red and Masson’s trichrome. The fibrotic changes were assessed by collagen deposition. The collagen content was determined by quantitative image analysis. Values were expressed as mean 6 SEM. Results: Significant diffuse histological changes were found in ventricles of rats in the BPA group (p!0.05). The BPA group had a greater mean collagen (2.2 6 0.6%) compared to corn oil (1.5 6 0.6%) and control group (1.5 6 0.2%) although differences were not statistically significant. Conclusions: Our data from this translational study suggest that chronic exposure to BPA may lead to cardiovascular fibrosis in rats through increased collagen deposition in the myocardium. However, clinical data in patients with prolonged BPA exposure are needed.