Comparison of muscle contractile properties between mTOR− and RAmKO mice
| Mice | Control | mTOR−/RAmKO | % Control |
| Soleus muscle | |||
| mTOR | |||
| Mass (mg) | 7.6 ± 0.4 | 7.5 ± 0.3 | 98.7 |
| Po (mN)a | 141.6 ± 33.2 | 104.3 ± 24.0c | 73.6 |
| sPo (mN/mm2)a | 187.9 ± 42.0 | 134.5 ± 37.1c | 71.6 |
| Pt (mN)a | 26.4 ± 3.7 | 16.2 ± 4.1d | 61.4 |
| TTP (ms)a | 82.7 ± 11.1 | 171.5 ± 73.8d | 207.4 |
| RT50% (ms)a | 131.7 ± 45.3 | 375.4 ± 228.2c | 285.0 |
| F20% (ms)a | 85.1 ± 14.5 | 41.1 ± 18.9d | 48.3 |
| Raptor | |||
| Mass (mg) | 7.1 ± 0.9 | 6.5 ± 0.9 | 90.9 |
| Po (mN)a | 155.6 ± 24.6 | 141.7 ± 11.0 | 91.0 |
| sPo (mN/mm2)a | 211.5 ± 38.7 | 212.4 ± 19.3 | 100.4 |
| TA muscle | |||
| mTOR | |||
| Mass (mg) | 37.5 ± 1.2 | 32.7 ± 2.2d | 87.2 |
| Po (mN)a | 536.3 ± 100.7 | 332.0 ± 55.4d | 61.9 |
| Po (mN)b | 567.1 ± 79.1 | 359.7 ± 34.8d | 63.4 |
| sPo (mN/mg)b | 15.1 ± 2.2 | 11.0 ± 1.4c | 73.0 |
| Pt (mN)b | 106.4 ± 25.8 | 60.5 ± 9.5d | 56.7 |
| TTP (ms)b | 31.5 ± 2.4 | 42.4 ± 9.3 | 134.6 |
| RT50% (ms)b | 33.2 ± 3.8 | 58.0 ± 10.9d | 174.7 |
| Deficit (%)b | −12.7 ± 5.0 | −56.0 ± 12.9d | −340.9 |
| Raptor | |||
| Mass (mg) | 41.0 ± 2.4 | 36.2 ± 1.7d | 88.5 |
| Po (mN)b | 607.1 ± 35.7 | 497.0 ± 55.2d | 81.9 |
| sPo (mN/mg)b | 14.9 ± 1.4 | 13.8 ± 1.8 | 92.5 |
| Deficit (%)b | −12.0 ± 3.5 | −12.2 ± 7.3 | 1.5 |
| Mice | Control | mTOR−/RAmKO | % Control |
| Soleus muscle | |||
| mTOR | |||
| Mass (mg) | 7.6 ± 0.4 | 7.5 ± 0.3 | 98.7 |
| Po (mN)a | 141.6 ± 33.2 | 104.3 ± 24.0c | 73.6 |
| sPo (mN/mm2)a | 187.9 ± 42.0 | 134.5 ± 37.1c | 71.6 |
| Pt (mN)a | 26.4 ± 3.7 | 16.2 ± 4.1d | 61.4 |
| TTP (ms)a | 82.7 ± 11.1 | 171.5 ± 73.8d | 207.4 |
| RT50% (ms)a | 131.7 ± 45.3 | 375.4 ± 228.2c | 285.0 |
| F20% (ms)a | 85.1 ± 14.5 | 41.1 ± 18.9d | 48.3 |
| Raptor | |||
| Mass (mg) | 7.1 ± 0.9 | 6.5 ± 0.9 | 90.9 |
| Po (mN)a | 155.6 ± 24.6 | 141.7 ± 11.0 | 91.0 |
| sPo (mN/mm2)a | 211.5 ± 38.7 | 212.4 ± 19.3 | 100.4 |
| TA muscle | |||
| mTOR | |||
| Mass (mg) | 37.5 ± 1.2 | 32.7 ± 2.2d | 87.2 |
| Po (mN)a | 536.3 ± 100.7 | 332.0 ± 55.4d | 61.9 |
| Po (mN)b | 567.1 ± 79.1 | 359.7 ± 34.8d | 63.4 |
| sPo (mN/mg)b | 15.1 ± 2.2 | 11.0 ± 1.4c | 73.0 |
| Pt (mN)b | 106.4 ± 25.8 | 60.5 ± 9.5d | 56.7 |
| TTP (ms)b | 31.5 ± 2.4 | 42.4 ± 9.3 | 134.6 |
| RT50% (ms)b | 33.2 ± 3.8 | 58.0 ± 10.9d | 174.7 |
| Deficit (%)b | −12.7 ± 5.0 | −56.0 ± 12.9d | −340.9 |
| Raptor | |||
| Mass (mg) | 41.0 ± 2.4 | 36.2 ± 1.7d | 88.5 |
| Po (mN)b | 607.1 ± 35.7 | 497.0 ± 55.2d | 81.9 |
| sPo (mN/mg)b | 14.9 ± 1.4 | 13.8 ± 1.8 | 92.5 |
| Deficit (%)b | −12.0 ± 3.5 | −12.2 ± 7.3 | 1.5 |
Muscle contractile properties of 9-wk-old mTOR and raptor mice were assessed by recording isometric forces in response to electrical stimulation. The following data were measured: muscle mass, Po, sPo, Pt, TTP, RT50%, time taken for maximal twitch tension to fall by 20% (F20%), and the percentage of force deficit following repetitive eccentric contractions (deficit). The data indicate mean ± SD (n > 4 mice/group).
Muscle electrical stimulation.
Nerve electrical stimulation.
P < 0.05.
P < 0.01.