Table 1.

Physiological and morphometric properties of Mstn−/− and C57BL/6 wild-type EDL muscles

Gender (age, months)Mstn−/− EDLC57BL/6 wild-type EDLP*
Maximal tetanic tension, mNMale (7)242 ± 22 (14)278 ± 14 (12)0.189
Male (2)164 ± 4 (3)166 ± 1 (4)0.5
Female (10)251 ± 18 (6)297 ± 12 (4)0.106
Specific tetanic tension, N/gMale (7)9.4 ± 0.99 (13)17.8 ± 0.92 (9)<0.001
Male (2)8.9 ± 0.63 (3)17.2 ± 0.99 (4)0.001
Female (10)11.0 ± 0.92 (6)27.2 ± 1.45 (4)<0.001
Specific tetanic tension, N/mm2Male (7)80.4 ± 14.5 (5)135.2 ± 7.8 (5)0.010
Maximal twitch force, mNMale (7)65.6 ± 5.46 (14)57.5 ± 2.81 (12)0.204
Twitch/tetanus ratioMale (7)0.275 ± 0.035 (14)0.21 ± 0.03 (12)<0.001
Contraction time, msMale (7)19.4 ± 0.33 (14)23.7 ± 0.56 (12)<0.001
Relaxation time, msMale (7)17.8 ± 1.10 (14)24.8 ± 1.40 (12)0.001
Wet weight, mgMale (7)26.4 ± 0.40 (13)15.9 ± 0.68 (9)<0.001
Male (2)18.6 ± 0.90 (3)9.7 ± 0.48 (4)0.003
Female (10)23.1 ± 0.79 (6)10.9 ± 0.21 (6)<0.001
CSA, mm2Male (7)3.17 ± 0.35 (5)2.07 ± 0.06 (5)0.035
Mitochondria number per unit areaMale (2)30.3 ± 0.55 (4)41.3 ± 0.69 (4)<0.001
  • Values are given as means together with mean standard error, and number of muscles examined is given in parentheses. For statistical analysis, the unpaired t test (*) was used. P < 0.05 was considered significant.