Figure 2. Force- [P_i] relations in fast and slow skeletal muscle at different temperature.

Maximal isometric force obtained in the presence of different [P_i] normalized over control force in P_i-free conditions. A, force-[P_i] relation of psoas myofibrils at 5 °C (•) and 15 °C (○). B, force-[P_i] relation of soleus myofibrils at 15 °C (•) and 20 °C (○). Continuous lines: hyperbolic fittings of force-[P_i] relations obtained at 15 °C in both muscle types; dashed lines: asymptotes of force-[P_i] relations. Results of hyperbolic fittings are reported in Table 1.