Figure 5. Effects of MHC composition on the normalized stretch activation response of rat skinned myocardium.

The force responses following a stretch of 1% of muscle length from thyroidectomized (0%α-MHC; A) and hyperthyroid (100%α-MHC; B) rat myocardium are superimposed. In each trace, the force response was normalized to the prestretch isometric force (corresponding to the zero baseline). In this case the level of Ca²⁺ activation was maximal (i.e. P/P_o= 1.00 for both A and B).