title: Bisphenol A and 17β-estradiol promote arrhythmia in the female heart via alteration of calcium handling.
abstract: BACKGROUND
  There is wide-spread human exposure to bisphenol A (BPA), a ubiquitous estrogenic endocrine disruptor that has been implicated as having potentially harmful effects on human heart health. Higher urine BPA concentrations have been shown to be associated with cardiovascular diseases in humans. However, neither the nature nor the mechanism(s) of BPA action on the heart are understood.
  
  
  RESULTS
  The rapid (<7 min) effects of BPA and 17β-estradiol (E2) in the heart and ventricular myocytes from rodents were investigated in the present study. In isolated ventricular myocytes from young adult females, but not males, physiological concentrations of BPA or E2 (10⁻⁹ M) rapidly induced arrhythmogenic triggered activities. The effects of BPA were particularly pronounced when combined with estradiol. Under conditions of catecholamine stimulation, E2 and BPA promoted ventricular arrhythmias in female, but not male, hearts. The cellular mechanism of the female-specific pro-arrhythmic effects of BPA and E2 were investigated. Exposure to E2 and/or BPA rapidly altered myocyte Ca²⁺ handling; in particular, estrogens markedly increased sarcoplasmic reticulum (SR) Ca²⁺ leak, and increased SR Ca²⁺ load. Ryanodine (10⁻⁷ M) inhibition of SR Ca²⁺ leak suppressed estrogen-induced triggered activities. The rapid response of female myocytes to estrogens was abolished in an estrogen receptor (ER) β knockout mouse model.
  
  
  CONCLUSIONS
  Physiologically-relevant concentrations of BPA and E2 promote arrhythmias in a female-specific manner in rat hearts; the pro-arrhythmic actions of estrogens are mediated by ERβ-signaling through alterations of myocyte Ca²⁺ handling, particularly increases in SR Ca²⁺ leak. Our study provides the first experimental evidence suggesting that exposure to estrogenic endocrine disrupting chemicals and the unique sensitivity of female hearts to estrogens may play a role in arrhythmogenesis in the female heart.
authors: Department of Pharmacology and Cell Biophysics, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America.
authors: Sujuan
authors: S
authors: Yan
authors: Yamei
authors: Y
authors: Chen
authors: Min
authors: M
authors: Dong
authors: Weizhong
authors: W
authors: Song
authors: Scott M
authors: SM
authors: Belcher
authors: Hong-Sheng
authors: HS
authors: Wang
mesh_terms: D000818:Animals; D001145:Arrhythmias, Cardiac / Q000139:chemically induced* / Q000378:metabolism / Q000473:pathology*; D001559:Benzhydryl Compounds; D020013:Calcium Signaling / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D052244:Endocrine Disruptors / Q000494:pharmacology*; D004958:Estradiol / Q000494:pharmacology*; D047629:Estrogen Receptor beta / Q000172:deficiency / Q000235:genetics; D004967:Estrogens / Q000494:pharmacology; D005260:Female; D055786:Gene Knockout Techniques; D006321:Heart / Q000187:drug effects*; D006352:Heart Ventricles / Q000187:drug effects / Q000473:pathology; D008297:Male; D051379:Mice; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000473:pathology; D010636:Phenols / Q000494:pharmacology*; D051381:Rats; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism; D012727:Sex Characteristics; D013997:Time Factors; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D052244:Endocrine Disruptors; D004958:Estradiol; D047629:Estrogen Receptor beta; D004967:Estrogens; D010636:Phenols; C006780:bisphenol A; D000098826:Bisphenol A Compounds