Table 2.
Comparison of mechanical parameters between myofibrils obtained from ARVMs cultured for 1 day and ARVMs maintained in serum-free medium for 3 days.
| ARVM Day 1 (N, n) | ARVM Day 3 (N, n) | P | |
|---|---|---|---|
| Sarcomere length (μm) | 2.24 ± 0.09 (6, 19) | 2.25 ± 0.07 (8, 9) | ns |
| Resting tension (mN/mm2) | 6.8 ± 3.5 (6, 17) | 7.3 ± 3.2 (8, 19) | ns |
| Maximal tension (mN /mm2) | 146.8 ± 51.7 (6, 14) | 135.8 ± 47.6 (8, 18) | ns |
| KACT (s−1) | 5.37 ± 0.95 (6, 18) | 4.05 ± 0.98 (8, 19) | P < 0.05 |
| KTR (s−1) | 5.20 ± 0.89 (6, 17) | 4.90 ± 0.95 (8, 19) | ns |
| Linear relaxation duration (ms) | 53.4 ± 17.7 (6, 16) | 34.2 ± 8.5 (8, 14) | P < 0.05 |
| Exponential relaxation rate (s−1) | 10.8 ± 4.8 (6, 14) | 10.2 ± 5.2 (8, 16) | ns |
Myofibrils are fully calcium activated (pCa 4.5) and fully relaxed (pCa 9) by fast solution switching. Data presented with mean ± SEM.