Table 1.
Myofibril active force sarcomere length dependence, kinetics of force development and relaxation, and the parameters describing the passive mechanical myofibril properties. Data are shown as mean ± SEM.
| Sample ID | Fmax at the SL shown below | Time-course parameters of myofibril activation and relaxation at SL 2.0 µm | Mechanical Parameters | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1.8 µm (kPa) | 2.0 µm (kPa) | 2.2 µm (kPa) | kACT (s−1) | kTR (s−1) | tLIN (ms) | kLIN (s−1) | kREL (s−1) | Slack SL (µm) | A | ||
| Donor | KN1 | 47 ± 4 (10) | 101 ± 7 (20) | 109 ± 8 (13) | 0.73 ± 0.06 (19) | 0.63 ± 0.03 (19) | 105 ± 7 (17) | 0.44 ± 0.16 (17) | 16.8 ± 1.7 (15) | 1.89 ± 0.04 (9) | 544 ± 66 (9) |
| KN2 | 55 ± 8 (6) | 102 ± 9 (7) | 120 ± 16 (5) | 0.91 ± 0.13 (7) | 0.69 ± 0.07 (6) | 86 ± 11 (6) | 0.63 ± 0.18 (6) | 18.08 ± 1.2 (6) | 1.93 ± 0.03 (13) | 529 ± 66 (13) | |
| NL | NA | NA | NA | NA | NA | NA | NA | NA | 1.88 ± 0.04 (5) | 561 ± 46 (5) | |
| NK | NA | NA | NA | NA | NA | NA | NA | NA | 1.90 ± 0.04 (5) | 663 ± 123 (5) | |
| Combined donors | 50 ± 4 (16) | 101 ± 5 (27) | 112 ± 7 (18) | 0.78 ± 0.06 (26) | 0.64 ± 0.03 (25) | 100 ± 6 (23) | 0.49 ± 0.13 (23) | 17.1 ± 1.2 (21) | 1.91 ± 0.02 (32) | 559 ± 38 (32) | |
| fDCM | D1 | 58 ± 5 (4) | 107 ± 10 (4) | 134 ± 8 (4) | 0.72 ± 0.06 (4) | 0.62 ± 0.08 (4) | 71 ± 6 (4)* | 0.17 ± 0.07 (4) | 20.0 ± 1.5 (3) | 1.90 ± 0.03 (14) | 329 ± 33 (14)*** |
| D2 | 40 ± 5 (9) | 104 ± 11 (13) | 123 ± 13 (11) | 0.91 ± 0.10 (13) | 0.67 ± 0.04 (13) | 70 ± 5 (12)** | 0.68 ± 0.28 (11) | 22.32 ± 1.6 (12)* | 1.94 ± 0.02 (21) | 324 ± 36 (21)*** | |
| D15 | 49 ± 6 (8) | 88 ± 10 (10) | 109 ± 7 (7) | 0.88 ± 0.06 (11) | 0.76 ± 0.06 (10)* | 79 ± 7 (9)* | 0.37 ± 0.20 (9) | 23.1 ± 1.7 (9)* | 1.90 ± 0.06 (6) | 368 ± 41 (6)* | |
| TTNtv | D6 | 52 ± 4 (6) | 96 ± 6 (7) | 114 ± 7 (7) | 0.82 ± 0.05 (7) | 0.68 ± 0.07 (7) | 97 ± 7 (7) | 0.52 ± 0.10 (7) | 15.5 ± 0.8 (7) | 1.86 ± 0.03 (18) | 354 ± 37 (18)*** |
| D7 | 38 ± 4 (8) | 98 ± 12 (8) | 108 ± 7 (8) | 0.87 ± 0.12 (8) | 0.61 ± 0.05 (8) | 98 ± 4 (8) | 0.09 ± 0.19 (8) | 19.3 ± 1.6 (8) | 1.90 ± 0.02 (27) | 367 ± 46 (27)*** | |
| D9 | 52 ± 4 (17) | 94 ± 4 (18) | 116 ± 6 (18) | 0.90 ± 0.07 (18) | 0.74 ± 0.03 (18)* | 98 ± 7 (17) | 0.52 ± 0.6 (18) | 20.0 ± 0.9 (17) | 1.90 ± 0.03 (24) | 348 ± 40 (24)*** | |
The number of measurements obtained on different myofibrils is indicated in parentheses. *P < 0.05, **P < 0.01, ***P < 0.001 (one-way ANOVA analysis) vs combined donors. The fDCM samples have contractile protein mutations, D1 (TNNC3 G159D), D2 (TNNI1 K36Q) and D15 (MYH7 E1426K). NA, data were not acquired.