Objective To verify whether bisphenol A (BPA) exposure would affect heart ejection in mice, and explore the underlying mechanisms.
Methods C57/BL6 male mice were given daily subcutaneous injection of BPA at 1, 5, and 10 mg/kg (exposure groups) or normal saline (control group) for four consecutive weeks. Ultrasound device was performed to observe the changes of left ventricular morphology and function. By Western blot test, related protein expression levels in mice ventricular tissue were determined.
Results Compared with the control group, the 10 mg/kg BPA exposure group showed significantly decreased left ventricular ejection fraction (LVEF)(64.79±6.17)% vs (57.53±3.03)%, P < 0.05 and left ventricular fractional shortening (LVFS)(34.46±2.62)% vs (29.01±1.74)%, P < 0.05; however, the level of left ventricular end-diastolic volume (LVEDV) was in creased(32.99±5.63) μL vs (37.48±2.72) μL, P < 0.05. The BPA exposure significantly increased the protein expression levels of H2A histone family member X (γH2AX). Atrial natriuretic peptide (ANP) tended to increase firstly and then decrease. In addition, the elevated phosphorylation levels of extracellular regulated protein kinase (ERK) and serine/threonine-protein kinase 1 (Akt) were also detected in the 5 and 10 mg/kg BPA exposure groups. However, we failed to observe any meaningful change of Brac-1 protein expression level after BPA exposure.
Conclusion Exposure to BPA can induce cardiac abnormality. With the increasing dose of BPA, LVEF and LVFS are decreased, which are negatively associated with the up-regulated expression of pAkt and pERK.
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