Table 7.
Muscle capillary and fiber type phenotypes in female wild-type and myoglobin knockout mice
| Female | WT | Mb−/− |
|---|---|---|
| C:F (#Capillaries/#Fibers) | ||
| Heart | na | na |
| GA-d | 1.49 ± 0.09 | 1.77 ± 0.08 |
| GA-s | 1.17 ± 0.02 | 1.24 ± 0.06 |
| SOL | 1.87 ± 0.10 | 2.07 ± 0.08 |
| EDL | 1.33 ± 0.8 | 1.42 ± 0.10 |
| PLT | 2.07 ± 0.11 | 1.86 ± 0.98 |
| Capillary density (#/mm2) | ||
| Heart | 2,482 ± 76 | 2,203 ± 81 |
| GA-d | 716 ± 50 | 850 ± 59 |
| GA-s | 407 ± 20 | 445 ± 15 |
| SOL | 888 ± 40 | 1,018 ± 42 |
| EDL | 733 ± 39 | 751 ± 53 |
| PLT | 938 ± 27 | 850 ± 52 |
| Mean fiber area (μm2) | ||
| Heart | na | na |
| GA-d | 2,169 ± 130 | 2,036 ± 109 |
| GA-s | 2,561 ± 114 | 2,347 ± 64 |
| SOL | 2,128 ± 84 | 2,091 ± 85 |
| EDL | 1,782 ± 54 | 1,781 ± 60 |
| PLT | 2,269 ± 145 | 2,294 ± 224 |
| Type 1 fibers (%) | ||
| Heart | na | na |
| GA-d | 32.3 ± 1.2 | 36.1 ± 1.4 |
| GA-s | 0.4 ± 0.2 | 0.4 ± 0.2 |
| SOL | 44.8 ± 1.5 | 46.2 ± 1.5 |
| EDL | 15.0 ± 1.3 | 16.6 ± 0.1 |
| PLT | 40.9 ± 2.1 | 36.0 ± 2.4 |
| Type 2 fibers (%) | ||
| Heart | na | na |
| GA-d | 67.7 ± 1.2 | 63.9 ± 1.4 |
| GA-s | 99.6 ± 0.2 | 99.6 ± 0.2 |
| SOL | 55.6 ± 1.6 | 54.5 ± 1.1 |
| EDL | 85.0 ± 1.3 | 83.1 ± 0.8 |
| PLT | 59.1 ± 2.1 | 64.0 ± 2.4 |
EDL, extensor digitorum longus; GA-d, deep gastrocnemius; GA-s, superficial gastrocnemius; Mb−/−, myoglobin knockout; SOL, soleus; PLT, plantaris; WT, wild type.
n = 8–10 per genotype; statistics for genotype effects provided in Table 5.