Figure 9.

Deletion of CAIII in mouse soleus muscle minimizes the rise of resting tension during fatigue contractions under acidosis stress. (A) During 300 s tetanic contractions, there was a rise of resting tension in the first 100 s. Acidotic extracellular pH (30%CO₂) significantly augmented this rise in WT soleus muscle, which was minimized in Car3-KO muscle. (B) Corresponding with the rise of resting tension, active tetanic tension development dropped rapidly during the first 100 s of fatigue contractions, most severe in WT soleus muscle at acidotic pH, which was minimized in Car3-KO muscle. The data are presented as mean ± SE. N = 6 mice each in WT and Car3-KO groups. ^*P < 0.05 vs. WT. ^#P < 0.05 vs. 30%CO₂. Statistical test was performed using two-way ANOVA and adjusted mean comparison of Bonferroni test between the four groups (for WT and Car3-Ko with 5% and 30% CO₂, DF = 3, F = 165.4 and P was close to 0).