Table 1.
6-Mo | 9-Mo | 18-Mo | 26-Mo | 30-Mo | |
Body weight, g | 399 ±19* | 512 ± 15 | 577 ± 25 | 600 ± 47* | 566 ± 76 |
Soleus | |||||
Wet weight, mg | 150 ± 8* | 202 ± 20 | 188 ± 3 | 191 ± 18 | 167 ± 15* |
mg/g BW | 0.38 ± 0.01 | 0.394 ± 0.033 | 0.32 ± 0.015* | 0.32 ± 0.01* | 0.30 ± 0.013* |
Plantaris | |||||
Wet weight, mg | 392 ± 23* | 486 ± 24 | 490 ± 25 | 410 ± 24* | 352 ± 28* |
mg/g BW | 1.35 ± 0.078 | 1.36 ± 0.112 | 1.14 ± 0.076* | 0.93 ± 0.088* | 0.76 ± 0.06* |
Medial gastrocnemius | |||||
Wet weight, mg | 888 ± 45* | 1110 ± 53 | 1036 ± 36 | 896 ± 81* | 731 ± 66* |
mg/g BW | 2.22 ± 0.076 | 2.17 ± 0.087 | 1.81 ± 0.14* | 1.49 ± 0.12* | 1.30 ± 0.10* |
Tibialis anterior | |||||
Wet weight, mg | 734 ± 41* | 931 ± 45 | 903 ± 22 | 821 ± 68* | 669 ± 47* |
mg/g BW | 1.84 ± 0.054 | 1.82 ± 0.06 | 1.52 ± 0.117* | 1.37 ± 0.123* | 1.21 ± 0.249* |
Extensor digitorum longus | |||||
Wet weight, mg | 173 ± 8* | 221 ± 11 | 215 ± 7 | 208 ± 19 | 170 ± 16* |
mg/g BW | 0.43 ± 0.006 | 0.43 ± 0.014 | 0.36 ± 0.023* | 0.35 ± 0.013* | 0.30 ± 0.042* |
Notes: Body weight (g) and muscle weight for male Fisher 344–Brown Norway F1 hybrid rats at various ages (n = 6–8 per age group). Muscle weight is expressed as a wet weight (mg) and normalized to body weight (mg wet weight/g BW). Data are expressed as mean ± standard deviation.
A significant difference (p < .001) from the 9-mo age group.