Fig. 6
From: A new myofilament contraction model with ATP consumption for ventricular cell model
The ATP hydrolysis rate during the step experiment under the isotonic contraction mode. The external force was released from 60 to 30 mN/mm2 (light gray), 15 mN/mm2(dark gray), and 5 mN/mm2 (black) in panels a through d (200 ms). a F ext, b halfSL, c v ATPase, d h p (upper traces) and h w (lower traces), e phase L 1–L 4 of halfSL change on the expanded time scale (70 ms), f load–velocity (dh p /dt) relation, g load–v ATPase. In b the notation of the different phases of relaxation, L 1–L 4, are indicated in e (F ext 60 → 5 mN/mm2). The [Ca2+] was 0.647 µM. a–d The gradation in color from gray to black is used to refer to the step size of F ext, as indicated in a, during the test pulse. The relaxation rate in f and g, measured between 79 and 80 ms, was plotted against F ext on the x-axis