Table 2.
Effects of six weeks of low intensity vibration training on histological assessments of oxidative capacity, as indicated by NADH reactivity and capillarity, and fiber type distribution of tibialis anterior and soleus muscles of mice that maintained normal physical activity and those that had restricted physical activity.
| Sham-Active | Vibrated-Active | Sham-Restricted | Vibrated-Restricted | P-values for Two-Way ANOVA | |||
|---|---|---|---|---|---|---|---|
| Main effect of Vibration | Main effect of Activity | Interaction (Vibration × Activity) | |||||
| Tibialis anterior muscle | |||||||
| NADH-positive fibers (%) | 64.4 (4.7) | 69.1 (3.7) | 57.6 (2.6) | 60.2 (2.6) | 0.292 | 0.033 | 0.760 |
| Capillaries per fiber | 3.73 (0.05) | 3.98 (0.22) | 3.46 (0.43) | 3.53 (0.21) | 0.641 | 0.309 | 0.805 |
| Type 2a fibers (%) | 6.8 (0.2) | 7.5 (1.4) | 4.4 (1.4) | 5.1 (0.2) | 0.649 | 0.168 | 0.996 |
| Type 2x fibers (%) | 43.6 (0.8) | 33.3 (5.0) | 12.3 (2.9) | 18.2 (2.9) | 0.716 | 0.003 | 0.197 |
| Type 2b fibers (%) | 49.6 (0.9) | 59.2 (6.0) | 83.3 (1.5) | 76.6 (2.7) | 0.836 | 0.005 | 0.264 |
| Soleus muscle | |||||||
| NADH-positive fibers (%) | 59.9 (2.0) | 59.6 (1.3) | 57.9 (3.7) | 64.5 (2.7) | 0.217 | 0.559 | 0.185 |
| Capillaries per fiber | 3.53 (0.10) | 3.26 (0.21) | 3.16 (0.22) | 3.91* (0.34) | - | - | 0.043 |
| Type 1 fibers (%) | 36.0 (0.7) | 32.2 (2.2) | 34.8 (2.2) | 34.6 (1.2) | 0.269 | 0.724 | 0.329 |
| Type 2a fibers (%) | 53.9 (0.4) | 56.5 (1.6) | 57.7 (1.8) | 56.8 (0.8) | 0.518 | 0.141 | 0.198 |
| Type 2x fibers (%) | 8.5 (1.3) | 9.2 (1.2) | 5.3 (3.0) | 6.0 (0.7) | 0.664 | 0.058 | 0.984 |
| Type 2b fibers (%) | 1.6 (1.0) | 2.2 (1.0) | 2.2 (0.5) | 2.7 (1.1) | 0.644 | 0.618 | 0.970 |
| Type 1 fiber CSA (μm2) | 1938.4 (151.2) | 1872.6 (98.7) | 1692.2 (136.5) | 2026.9 (119.9) | 0.312 | 0.725 | 0.142 |
| Type 2a fiber CSA (μm2) | 2302.8 (205.1) | 2430.9 (155.0) | 2370.0 (154.1) | 2440.0 (150.8) | 0.579 | 0.830 | 0.870 |
| Type 2x fiber CSA (μm2) | 2102.0 (138.2) | 1910.9 (109.7) | 2175.6 (28.2) | 2124.8 (232.2) | 0.451 | 0.373 | 0.660 |
| Type 2b fiber CSA (μm2) | 1799.7 (666.2) | 1606.7 (330.0) | 2154.4 (191.6) | 1933.0 (653.0) | 0.699 | 0.528 | 0.979 |
Values are means (SE). NADH, nicotinamide adenine dinucleotide. CSA, cross-sectional area.
*
Significantly different from Sham-Restricted