Figure 2.

P4 inhibits BPA-induced alterations of Ca²⁺ handling in female rat ventricular myocytes. (a) Representative images of Ca²⁺ sparks in quiescent myocytes under control, BPA, BPA + P4, or BPA + P4 + RU486 (1 μM). (b) Representative Ca²⁺ transients elicited by caffeine after field stimulation under various treatments. The amplitudes of caffeine-induced Ca²⁺ transients are indications of SR Ca²⁺ load. (c) Mean Ca²⁺ sparks frequency in myocytes under various treatments (n = 7 to 9 myocytes from four hearts). (d) Caffeine-induced Ca²⁺ transients amplitude (CaT_caff) in myocytes under various treatments (n = 8 to 10 myocytes from four hearts). BPA and P4 at 1 nM for all experiments. **P < 0.01; ^#P > 0.1 versus control; ^†P < 0.01 (one-way analysis of variance). Error bars are standard error of the mean.