Summary of steady-state mechanical measurements
| Measurement . | Murine LV (8) (Control) . | Murine LV (7) (1 μM NEM-S1) . | Porcine LA (12) (Control) . | Porcine LV (15) (Control) . |
|---|---|---|---|---|
| Po (mN mm−2) | 21.5 ± 2.4 | 19.5 ± 1.9 | 22.6 ± 2.7 | 17.9 ± 0.9 |
| Prest (mN mm−2) | 0.8 ± 0.1 | 1.3 ± 0.2 | 1.1 ± 0.3 | 0.5 ± 0.1 |
| nH | 4.0 ± 0.2 | 3.6 ± 0.2 | 3.2 ± 0.1 | 4.6 ± 0.1b |
| pCa50 | 5.78 ± 0.01 | 5.82 ± 0.02 | 5.69 ± 0.02a | 5.70 ± 0.01a |
| ktr (s−1) | 29.8 ± 2.1 | 28.2 ± 2.1 | 14.5 ± 0.8a | 2.9 ± 0.2a,b |
| Measurement . | Murine LV (8) (Control) . | Murine LV (7) (1 μM NEM-S1) . | Porcine LA (12) (Control) . | Porcine LV (15) (Control) . |
|---|---|---|---|---|
| Po (mN mm−2) | 21.5 ± 2.4 | 19.5 ± 1.9 | 22.6 ± 2.7 | 17.9 ± 0.9 |
| Prest (mN mm−2) | 0.8 ± 0.1 | 1.3 ± 0.2 | 1.1 ± 0.3 | 0.5 ± 0.1 |
| nH | 4.0 ± 0.2 | 3.6 ± 0.2 | 3.2 ± 0.1 | 4.6 ± 0.1b |
| pCa50 | 5.78 ± 0.01 | 5.82 ± 0.02 | 5.69 ± 0.02a | 5.70 ± 0.01a |
| ktr (s−1) | 29.8 ± 2.1 | 28.2 ± 2.1 | 14.5 ± 0.8a | 2.9 ± 0.2a,b |
All values are expressed as mean ± SEM, with the number of skinned myocardial preparations listed in parentheses. Po, maximal Ca2+-activated tension at pCa 4.5; Prest, Ca2+-independent tension at pCa 9.0; nH, Hill coefficient for Ca2+-activated force–pCa relationship; pCa50, pCa required for half-maximal activation; ktr, maximal rate of force redevelopment at pCa 4.5.
Significantly different from control murine LV myocardium (P < 0.05).
Significantly different from porcine atrial myocardium (P < 0.05).