Table 4. Parametrization of the model for different species.
| Mouse | Rat | Human | |
|---|---|---|---|
| Parametrization with variable XB unbinding rates (q = 0.5) | |||
| K DI | 4 ⋅ 10−3 | 8.7 ⋅ 10−3 | 2.6 ⋅ 10−3 |
| k M- (ms−1) | 0.5 | 0.09 | 0.016 |
| Model TPT (ms) | 33 | 41 | 170 |
| Model RT50 (ms) | 29 | 30 | 124 |
| Model RT90 (ms) | 49 | 51 | 217 |
| Model RT95 (ms) | 56 | 57 | 247 |
| Parametrization with constant XB unbinding rates (q = 1) | |||
| K DI | 4 ⋅ 10−3 | 8.7 ⋅ 10−3 | 3.3 ⋅ 10−3 |
| k M- (ms−1) | 2 | 0.3 | 0.049 |
| Model TPT (ms) | 33 | 37 | 157 |
| Model RT50 (ms) | 28 | 29 | 125 |
| Model RT90 (ms) | 49 | 55 | 250 |
| Model RT95 (ms) | 57 | 64 | 298 |
| Experimental data | |||
| TPT (ms) | 30–40 | 39 ± 6 | 147–172 |
| RT50 (ms) | 22–35 | 31 ± 5 | 109–125 |
| RT90 (ms) | 45–60 | ||
| RT95 (ms) | 334 ± 43 | ||
| References | [57–61] | [62] | [63, 64] |
Shown in this table are the changes to K DI, k M- needed to replicate mouse, rat and human dynamic muscle function. Also shown are metrics of time to peak tension (TPT) and 50%/90%/95% relaxation times (RT50, RT90, RT95) of the dynamic model. Results for force transient are also shown in Fig 7. The bottom section shows experimental data ranges used for parametrization of the models. Two sets of results are shown, corresponding to a constant crossbridge unbinding rate (q = 1 in Eq 22) and a crossbridge unbinding rate that is variable, modified by the average difference in free energy for the tropomyosin deformation (q = 0.5 in Eq 22)