Table 1.
Parameter | n | SL 1.9 μm |
SL 2.3 μm |
|||||||
---|---|---|---|---|---|---|---|---|---|---|
Tpass mN/mm2 | Tmax mN/mm2 | pCa50 | nH | Tpass mN/mm2 | Tmax mN/mm2 | pCa50 | nH | ΔpCa50 | ||
EPI | 14 | 0.5±0.1 | 25±4 | 5.52±0.02 | 4.3±0.1 | 1.5±0.2* | 23±3 | 5.61±0.02* | 3.6±0.2* | 0.09±0.01 |
ENDO | 14 | 0.6±0.1 | 22±2 | 5.56±0.02 | 3.5±0.1** | 2.4±0.2*,** | 20±1 | 5.75±0.03*,** | 4.3±0.3*,** | 0.19±0.01** |
Values are means±SEM. Passive (Tpass) and maximal active (Tmax) tensions in mN/mm2 were measured at pCa 9 and 4.5, respectively and at short and long sarcomere length (SL), on sub-epicardial (EPI), and sub-endocardial (ENDO). pCa50, pCa for half-maximal activation and nH, Hill coefficient were obtained by fitting the force–pCa relations. n is the number of cells
Significant difference from short SL (P<0.05).
Significant difference from sub-epicardial cells (P<0.05).