Differential Effect of Calsequestrin Ablation on Structure and Function of Fast and Slow Skeletal Muscle Fibers

Figure 6

Tension decline and residual tension after 2 seconds of high-frequency stimulation in EDL and Soleus of CASQ1-null and dCASQ-null mice. (a) and (b) When stimulated at high frequency (2 s, 140 Hz) EDL muscles of both CASQ1-null and dCASQ-null displayed a strong drop in tension (by about 80%) compared to WT. (c) and (d) Conversely, in Soleus muscle (stimulated at 90 Hz for 2 s) this effect was considerably less: compared to WT, tension was decreased by ~15% in CASQ1-null and 25% in dCASQ-null (EDL: WT 𝑛=8, CASQ1-null 𝑛=10, dCASQ null 𝑛=9, Soleus: WT 𝑛=8, CASQ1-null 𝑛=10, dCASQ null 𝑛=10). *Significantly different from WT; #significantly different from CASQ1-null.