Table 1.
Diaphragm Muscle Contractile Properties.
| Wild-Type (n = 7) | Mdx (n = 7) | mdx + Tempol In Vitro (n = 7) | mdx + Tempol In Vivo (n = 8) | Student’s t Test | |
|---|---|---|---|---|---|
| CT (ms) | 18.0 ± 1.8 | 20.5 ± 4.5 | 17.9 ± 1.5 | 20.2 ± 3.1 | $: p = 0.2196; †: p = 0.1796; £: p = 0.8777 |
| ½ RT (ms) | 23.5 ± 0.6 | 23.5 ± 0.5 | 23.2 ± 0.2 | 17.8 ± 3.9 | $: p = 0.9803; †: p = 0.1197; £: p = 0.0046 |
| Pt (N/cm2) | 5.1 ± 1.7 | 2.5 ± 0.7 | 2.7 ± 0.7 | 4.0 ± 1.2 | $: p = 0.0066; †: p = 0.4821; £: p = 0.0111 |
| Wmax (J/cm2) | 1.3 ± 0.5 | 0.7 ± 0.2 | 0.7 ± 0.4 | 1.5 ± 0.7 | $: p = 0.0276; †: p = 0.6852; £: p = 0.0085 |
| Pmax (W/cm2) | 9.0 ± 3.8 | 5.8 ± 0.9 | 4.7 ± 1.6 | 11.0 ± 4.9 | $: p = 0.0709; †: p = 0.1329; £: p = 0.0217 |
| Smax (L/Lo) | 0.32 ± 0.06 | 0.28 ± 0.07 | 0.24 ± 0.03 | 0.34 ± 0.10 | $: p = 0.3457; †: p = 0.1532; £: p = 0.1936 |
| Vmax (Lo/s) | 3.5 ± 1.3 | 3.8 ± 0.8 | 2.7 ± 0.9 | 4.5 ± 2.0 | $: p = 0.6766; †: p = 0.0353; £: p = 0.3433 |
Values (mean ± SD) for twitch contraction time (CT), twitch half-relaxation time (½ RT), peak twitch force (Pt), maximum mechanical work (Wmax), maximum mechanical power (Pmax), peak shortening (Smax), and peak shortening velocity (Vmax) of diaphragm muscle from the following groups: wild-type (n = 7), mdx (n = 7), mdx + tempol in vitro (n = 7) and mdx + tempol in vivo (n = 8). For the mdx + tempol in vitro group, diaphragm muscle preparations were studied in Krebs solution containing 1 mM tempol in vitro. The mdx + tempol in vivo group received 1 mM tempol in their drinking water for two weeks. Data were statistically compared by unpaired Student’s t tests with Welch’s correction where appropriate. $: Wild-Type vs. mdx; †: mdx vs. mdx Tempol in vitro; £: mdx vs. mdx Tempol in vivo.