Table 1.
FKBP12.6+/+ |
FKBP12.6−/− |
|||
---|---|---|---|---|
Control | ISO | Control | ISO | |
Force (mN/mm2) | 1.2 ± 0.2 | 2.1 ± 0.2* | 0.8 ± 0.1 | 1.5 ± 0.2* |
% Change | 45 | 43 | ||
dF/dTmax | 32 ± 6 | 63 ± 7* | 24 ± 2 | 47 ± 5* |
% Change | 47 | 47 | ||
Tau (ms) | 36 ± 3 | 27 ± 2* | 32 ± 2 | 24 ± 2* |
% Change | 22 | 23 |
Force was normalized to cross-sectional area (mN/mm2). Baseline was determined by averaging a total of 100 ms, 75 ms before, and 25 ms after the stimulus artefact. Peak amplitude (mN/mm2) was baseline to maximal force development. dF/dTmax was the maximal rate of force development (mN/mm2/s) during contraction. The time constant of decay, tau, was determined as the time to reach 37% of initial (maximal) value. Three to five consecutive contractions were averaged to obtain values of a representative contraction. Isoproterenol was added to a final concentration of 1 mM and values calculated at peak response. A total of eight experiments were performed for each group. Values are mean ± SE.
*P ≤ 0.02 within a group. There was no statistical significance between groups.