Table 2. Characteristics of the force-pCa relationships in skinned papillary muscle fibers.
pCa50 | Hill Coefficient | Maximal Force (mN mm−2) | pCa50 | Hill Coefficient | Maximal Force (mN mm−2) | |
Sarcomere Length | 1.9 µm | 1.9 µm | 1.9 µm | 2.3 µm | 2.3 µm | 2.3 µm |
Tnnt2 +/−/TGWT (n = 10) | 5.58±0.03 | 6.54±0.89 | 45.9±4.6 | 5.71±0.03 | 3.65±0.11 | 62.3±6.5 |
Tnnt2 +/−/TGK210Δ (n = 7) | 5.34±0.08 | 9.34±2.47 | 34.5±5.3 | 5.46±0.04 | 6.72±1.09 | 63.1±10.9 |
p | <0.01 | NS | NS | <0.01 | NS | NS |
pCa50, pCa required for generation of 50% of maximal force. n, number of skinned fibers studied, taken from a total of 6 hearts in each group. NS, not significant. Data: mean±SE. p values correspond to the comparison between Tnnt2 +/−/TGWT and Tnnt2 +/−/TGK210Δ fibers at the same sarcomere length.