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. 2001 Jan 15;530(Pt 2):263–272. doi: 10.1111/j.1469-7793.2001.0263l.x

Figure 3. Effects of 6 μm NEM-S1 on force-pCa relationships in skinned myocardium.

Figure 3

Force-pCa relationships were determined from skinned ventricular myocardium (n = 7) in the absence (0) and presence (1) of NEM-S1. Smooth lines were generated by fitting the mean data with the equation: Prel=[Ca2+]n/(kn+[Ca2+]n), where Prel is force as a fraction of maximal Ca2+-activated force (Po) or maximal total force (PTot), n is the Hill coefficient, and k is the [Ca2+] required for half-maximal activation (i.e. pCa50). Data points are means and the error bars are s.e.m. A, Ca2+-activated force-pCa relationship in the absence (pCa50= 5.85 ± 0.05, n2= 4.72 ± 0.38) and presence of NEM-S1 (pCa50= 5.95 ± 0.04, n2= 1.54 ± 0.07). B, total force-pCa relationship in the absence (pCa50= 5.86 ± 0.05, n2= 4.50 ± 0.69) and presence of NEM-S1 (pCa50= 6.09 ± 0.05, n2= 0.93 ± 0.22). Total force is the sum of Ca2+-independent and Ca2+-activated forces at each pCa.