Fig. 1.

Tension development and time to fatigue during a repetitive contractile period on extensor digitorum longus (EDL; A and B) and soleus (C and D) muscles. Relative tension (%) was developed at different time points of the contractile period in wild-type (WT; circles, A and C) and transgenic model of pulmonary TNF-α overexpression (Tg⁺) mice (triangles, A and C) (solid symbols: high Po₂; open symbols: low Po₂). Time to fatigue under different Po₂ in WT (open bars) and Tg⁺ (crossed bars) mice (B and D). Data were averaged from 9 muscles of 5 mice for WT and 7 muscles of 5 mice for Tg⁺. *P < 0.05, low vs. high Po₂ condition, two-way repeated-measures ANOVA; †P < 0.05, Tg⁺ vs. WT under the same Po₂ condition, two-way repeated-measures ANOVA.