Table 1.
Effect of MHC composition on steady-state mechanical properties of rat myocardium
| n | Ca2+-Activated Force in Trabeculae, mN/mm2 | nH | pCa50 | |
|---|---|---|---|---|
| 100% α-MHC | 12 | 41.4±2.3 | 4.06±0.32 | 5.78±0.01 |
| 60% α-MHC | 10 | 41.8±1.6 | 4.31±0.35 | 5.78±0.02 |
| 0% α-MHC | 10 | 31.3±1.6* | 4.13±0.36 | 5.79±0.01 |
Data are means ± SE; n, number of cardiac preparations. MHC, myosin heavy chain; Ca2+-activated force, difference between maximal force generated at pCa 4.5 and rest force generated at pCa 9.0; nH, Hill coefficient for the total force-pCa relationship; pCa50, pCa required for half-maximal force generation.
*
Significantly different from hyperthyroid (100% α-MHC) myocardium (P < 0.05).