Figure 6. Effects of PKA treatment on the stretch activation responses of TGS282A myocardium.
Force transients following a stretch of 2% of muscle length were recorded at [Ca2+] yielding a pre-stretch isometric force of ∼50% maximal before (black trace) and after PKA treatment (grey trace) in TGS282A-skinned myocardium. These representative transients are normalized to pre-stretch isometric force corresponding to the force baseline, which is arbitrarily set at zero, and demonstrate that PKA treatment significantly accelerated the overall stretch activation response in TGS282A-skinned myocardium. The stretch activation parameters that were investigated are represented in the trace and are described in detail in the text. PKA, protein kinase A; TG, transgenic.