FIGURE 5.

Relations of F₀ (solid circles) and (F₀ + F_SA) (open circles) versus pCa at the two [Mg²⁺]. The ordinate in both graphs is expressed as relative to F_0,max, the isometric force at saturating pCa in low Mg. Data from three fibers. Continuous lines are calculated from Hill equation using the best-fit parameters listed in the table

	n	pK
Low Mg	2.26 ± 0.18	5.94 ± 0.02
High Mg	1.89 ± 0.20	5.31 ± 0.03

below.