Table 1.
Ex vivo contractile properties of soleus and EDL muscles of Zmpste24+/+ and Zmpste24−/− mice
| Zmpste24+/+ | Zmpste24−/− | p value | |
|---|---|---|---|
| Soleus muscle (n) | (13) | (10) | |
| Pt (mN) | 26.4 ± 1.5 | 24.7 ± 2.7 | 0.507 |
| TPT (ms) | 35.0 ± 1.0 | 43.1 ± 3.8 | 0.026 |
| 1/2 RT (ms) | 4.0 ± 0.1 | 5.7 ± 0.8 | 0.022 |
| +dP/dt (N/s) | 1.7 ± 0.1 | 1.5 ± 0.2 | 0.510 |
| −dP/dt (N/s) | 3.3 ± 0.3 | 1.6 ± 0.2 | 0.002 |
| Active stiffness (N/m) | 269.3 ± 15.1 | 241.6 ± 22.7 | 0.301 |
| Passive stiffness (N/m) | 11.5 ± 0.4 | 16.5 ± 1.4 | <0.001 |
| EDL muscle (n) | (11) | (11) | |
| Pt (mN) | 69.5 ± 2.1 | 35.4 ± 2.6 | <0.001 |
| TPT (ms) | 19.3 ± 0.3 | 18.2 ± 1.5 | 0.475 |
| 1/2 RT (ms) | 1.8 ± 0.1 | 2.2 ± 0.1 | <0.001 |
| +dP/dt (N/s) | 7.3 ± 0.2 | 4.2 ± 0.4 | <0.001 |
| −dP/dt (N/s) | 21.4 ± 0.5 | 7.9 ± 1.3 | <0.001 |
| Active stiffness (N/m) | 433.6 ± 14.2 | 299.3 ± 22.2 | <0.001 |
| Passive stiffness (N/m) | 12.2 ± 0.5 | 18.2 ± 1.0 | <0.001 |
Mean ± SE
Pt peak twitch force, TPT time to peak twitch force, 1/2 RT one half relaxation time, +dP/dt maximal rate of tectanic force development, −dP/dt maximal rate of relaxation