Bisphenol A Exposure Modifies the Vasoactive Response of the Middle Cerebral Artery

Bisphenol A (BPA) is the most used widely synthetic compound for the manufacture of polycarbonate plastics and epoxy resins produced worldwide. Given its androgenic and estrogenic activities, BPA is an endocrine disruptor that is linked to neurological and vascular outcomes, including strokes. Therefore, this study aims to investigate the mechanisms by which a 24 h exposure to BPA (0.002-20 μM) modifies the contractile function of rat middle cerebral artery (MCA) smooth muscle cells (SMCs). Thus, MCA explants were isolated from Wistar rats, and the SMC-MCA vasoactive response was assessed using planar cell surface area, while the gene expression of proteins and ion channel subunits involved in the MCA vasoactive response was evaluated by real-time quantitative PCR. The exposure to BPA (0.02 and 2 μM) decreased the noradrenaline (NA) vasocontractile response and sodium nitroprusside (SNP) vasorelaxant response. Moreover, exposure to BPA (0.02 and 2 μM) increased the gene expression of the soluble guanyl cyclase protein and the large conductance Ca²⁺-activated K⁺ channels (1.1 α-subunit). These results suggest an impairment of the SMC-MCA vasoactive response induced by intermediate BPA concentrations, an effect not attained for the lowest or highest exposure concentrations (non-monotonic inverted U-shaped response). In summary, these findings suggest that BPA exposure modifies MCA vascular homeostasis by interfering with the nitric oxide (NO) pathway and may, thus, be involved in ischemic stroke development.