Figure 3.

BPA increases the number of mast cells and degranulation of pericardial mast cells during viral myocarditis. Female BALB/c mice were given 0 or 5 μg/kg BW BPA (0 BPA vs. 5 BPA) in drinking water for 2 weeks and injected with 10³ PFU CVB3 ip on day 0. BPA exposure continued from day 0 to 10 pi and hearts were harvested at day 10 pi during acute myocarditis. (A) Relative gene expression (RGE) of mast cells (cKit/ CD117) vs. the housekeeping gene Hprt was analyzed in whole hearts by qRT-PCR at day 10 pi comparing 0 to 5 μg BPA/kg BW groups. (0 BPA n = 10, 5 BPA n = 8). Toluidine blue was used to detect mast cell granules by histology and the total numbers of mast cells in the heart section were normalized to the size of the heart using an eyepiece grid (50). (B) Data show the mean ± SEM using the Mann-Whitney rank test (0 BPA n = 20, 5 BPA n = 20). A representative photo of (C) non-degranulating (NOT) and (D) degranulating (Degran) mast cells. Mast cell granules stain dark purple, magnification 400x, scale bar 30 μm. (E) Data show the mean ± SEM of 10 mice/group. Two-way ANOVA found significant results for degranulation (p < 0.0001) and BPA (p = 0.0006). *p < 0.05 indicates ad-hoc analysis comparing 0 vs. 5 BPA for degranulating cells (Degran). (F,G) Two-way ANOVA found significant results for degranulation p = 0.0001, but not for BPA for (F) myocardial and (G) vascular MCs, n = 10/group. (H) In contrast, 2-way ANOVA found significant results for degranulation (p < 0.0002) and BPA (p = 0.0004) for pericardial mast cells. After Tukey's multiple comparison test, 5 BPA was found to significantly increase degranulation in pericardial mast cells compared to control water (**p < 0.01).