Impact of OM on the dynamic XB parameters in PKA-treated WT and SA myocardial preparations. The effects of OM on dynamic XB parameters derived from stretch activation responses in PKA-treated WT and SA myocardial preparations are shown at pCa 6.0. (A and B)k_rel before and following OM incubation in WT (A) and SA (B) myocardial preparations. (C and D)k_df before and following OM incubation in WT (C) and SA (D) myocardial preparations. (E and F) P1 before and following OM incubation in WT (E) and SA (F) myocardial preparations. (G and H) P_df before and following OM incubation in WT (G) and SA (H) myocardial preparations. Data from multiple preparations from each heart were averaged, and six to seven myocardial preparations from three different hearts were used per group. Values are expressed as mean ± SEM. *, Significantly different compared with the corresponding pre-OM group; P < 0.05. &, Significantly different compared with the corresponding WT group.