Exposure to bisphenol-S (BPS), an ingredient that has replaced BPA in many items, caused irregular heartbeats in female lab rats, according to the study by Hong-Sheng Wang and colleagues published this 26 February 2015. The findings were “remarkably similar—if not identical to—what we find in BPA” Wang said.
Bisphenol S (BPS) is increasingly been used as a substitute for BPA in some “bisphenol A (BPA)-free” consumer goods and in thermal papers. Wide human exposure to BPS has been reported; however, the biological and potential toxic effects of BPS are poorly understood.
Objective: To elucidate the sex-specific rapid impact of BPS in rat hearts and its underlying mechanism.
Rapid effects of BPS in rat hearts were examined using electrophysiology, confocal and conventional fluorescence imaging, and immunoblot.
In female rat hearts, acute exposure to 10-9 M BPS increased heart rate and in the presence of catecholamine-induced stress condition, markedly increased the frequency of ventricular arrhythmia events. BPS increased the incidence of arrhythmogenic triggered activities in female ventricular myocytes, and altered myocyte Ca2+ handling, particularly spontaneous Ca2+ release from the sarcoplasmic reticulum. The dose responses of BPS’ actions were inverted-U shaped. The impact of BPS on myocyte Ca2+ handling was mediated by estrogen receptor β signaling and rapid increases in the phosphorylation of key Ca2+ handling proteins including ryanodine receptor and phospholamban. The pro-arrhythmic effects of BPS were female-specific; male rat hearts were not affected by BPS at the organ, myocyte and protein levels.
Rapid exposure to low-dose BPS has pro-arrhythmic impact on female rat hearts; these effects at the organ, cellular and molecular levels are remarkably similar to those reported for BPA. Evaluation of the bioactivity and safety of BPS and other BPA analogs is necessary before they are used as BPA alternatives in consumer products.
Sources and more information
- Chemical in BPA-Free Products Linked to Irregular Heartbeats, nationalgeographic news, FEBRUARY 25, 2015.
- Rapid Responses and Mechanism of Action for Low-Dose Bisphenol S on ex Vivo Rat Hearts and Isolated Myocytes: Evidence of Female-Specific Proarrhythmic Effects, Environ Health Perspect; DOI:10.1289/ehp.1408679, 26 February 2015, full study PDF.