Figure 10.

Analysis of Ca²⁺ dynamics for the protocol from Fig. 9 reveal that the small variations in spark rate lead to fluctuations in myoplasmic calcium that are governed by the fraction of channels in mode 2. (A) Ca²⁺-spark count. (B) [Ca²⁺]_i. (C) [Ca²⁺]_NSR. (D) Fraction of channels (FoC) in mode 2 (M2) when stretched (from 10 to 30 s) at 1 Hz, 2 Hz, and 4 Hz (n = 20 simulations). The myocyte is stretched and released from stretch continuously from 10 to 30 s. The beats before 10 s show the response without stretching. If the ROS-induced activation of RyRs were not present, this level of sparks would persist regardless of stretching. To see this figure in color, go online.